part I

have never found it, and, in our sense of the word, I am certain it is not there. An unbending, unchanging classification of animals would have been something foreign to all his logic; it is all very well, it becomes practically necessary, when we have to arrange our animals on the shelves of a museum or in the arid pages of a 'systematic' catalogue; and it takes a new complexion when, or if, we can attain to a real or historical classification, following lines of actual descent and based on proven facts of historical evolution. But Aristotle (as it seems to me) neither was bound to a museum catalogue nor indulged in visions either of a complete _scala naturae_ or of an hypothetical phylogeny. He classified animals as he found them; and, as a logician, he had a dichotomy for every difference which presented itself to his mind. At one time he divided animals into those with blood and those without, at another into the air-breathers and the water-breathers; into the wild and the tame, the social and the solitary, and so on in endless ways besides. At the same time he had a quick eye for the great natural groups, such 'genera' (as he called them) as Fish or Bird, Insect or Mollusc. So it comes to pass that, while he fashioned no hard and fast scheme of classification, and would undoubtedly (I hold) have thought it vain to do so, the threads of his several partial or temporary classifications come together after all, though in a somewhat hazy pattern, yet in a very beautiful and coherent parti-coloured web. And though his order is not always our order, yet a certain exquisite orderliness is of the very essence of his thought and style. It is the characteristic which Molière hits upon in _Les Femmes savantes_,--'Je m'attache _pour l'ordre_ au péripatétisme'.

Before he finishes the great chapter of which we have begun to speak he indicates that there are more ways than one of relating, or classifying, our facts; that, for instance, it may be equally proper and necessary to deal now with the animals and their several parts or properties, and at another time with the parts or properties as such, explaining and illustrating them in turn by the several animals which display or possess them. The 'Parts of Animals' is, then, a corollary, a necessary corollary, to the more anecdotal _Historia Animalium_. And yet again, there is a third alternative--to discuss the great functions or actions or potentialities of the organism, as it were first of all in the abstract, and then to correlate them with the parts which in this or that creature are provided and are 'designed' to effect them. This involves the conception and the writing of separate physiological treatises on such themes as Respiration, Locomotion, on Sleeping and Waking, and lastly (and in some respects the most ambitious, most erudite, and most astonishing of them all) the great account of the Generation of Animals.

So the whole range, we might say the whole conceivable range, of biological science is sketched out, and the greater part of the great canvas is painted in. But to bring it into touch with human life, and to make good its claim to the high places of philosophy, we must go yet farther and study Life itself, and what men call the Soul. So grows the great conception. We begin with trivial anecdote, with the things that fisherman, huntsman, peasant know; the sciences of zoology, anatomy, physiology take shape before our very eyes; and by evening we sit humbly at the feet of the great teacher of Life itself, the historian of the Soul. It is not for us to attempt to show that even here the story does not end, but the highest chapters of philosophy begin. Then, when we remember that this short narrative of ours is but the faintest adumbration of one side only of the philosopher's many-sided task and enterprise, we begin to rise towards a comprehension of Roger Bacon's saying, that 'although Aristotle did not arrive at the end of knowledge, he set in order all parts of philosophy'. In the same spirit a modern critic declares: 'Il n'a seulement défini et constitué chacune des parties de la science; il en a de plus montré le lien et l'unité'.

Aristotle, like Shakespeare, is full of old saws, tags of wisdom, jewels five words long. Here is such a one, good for teacher and pupil alike--Δει πιστευειν τον μανθανοντα {Dei pisteuein ton manthanonta}. It tells us that the road to Learning lies through Faith; and it means that to be a scholar one should have a heart as well as brains.

By reason partly of extraneous interpolation, but doubtless also through a lingering credulity from which even philosophers are not immune, we find in Aristotle many a strange story. The goats that breathe through their ears, the vulture impregnated by the wind, the eagle that dies of hunger, the stag caught by music, the salamander which walks through fire, the unicorn, the mantichore, are but a few of the 'Vulgar Errors' or 'Received Tenents' (as Sir Thomas Browne has it) which are perpetuated, not originated, in the _Historia Animalium_. Some of them come, through Persia, from the farther East: and others (we meet with them once more in Horapollo the Egyptian priest) are but the exoteric or allegorical expression of the arcana of ancient Egyptian religion.

So it comes to pass that for two thousand years and throughout all lands men have come to Aristotle, and found in him information and instruction--that which they desired. Arab and Moor and Syrian and Jew treasured his books while the western world sat in darkness; the great centuries of Scholasticism hung upon his words; the oldest of our Universities, Bologna, Paris, Oxford, were based upon his teaching, yea, all but established for his study. Where he has been, there, seen or unseen, his influence remains; even the Moor and the Arab find in him, to this day, a teacher after their own hearts: a teacher of eternal verities, telling of sleep and dreams, of youth and age, of life and death, of generation and corruption, of growth and of decay: a guide to the book of Nature, a revealer of the Spirit, a prophet of the works of God.

The purpose of these little essays, I have been told (though I had half forgotten it), is to help though ever so little to defend and justify the study of the language and the vast literature of Greece. It is a task for which I am unfitted and unprepared. When Oliver Goldsmith proposed to teach Greek at Leyden, where he 'had been told it was a desideratum', the Principal of that celebrated University met him (as we all know) with weighty objections. 'I never learned Greek', said the Principal, 'and I don't find that I have ever missed it. I have had a Doctor's cap and gown without Greek. I have ten thousand florins a year without Greek; and, in short', continued he, 'as I don't know Greek, I do not believe there is any good in it.'--I have heard or read the story again and again, for is it not written in the _Vicar of Wakefield_? But I never heard that any man, not Goldsmith himself, attempted to confute the argument. I agree for the most part with the Principal, and can see clearly that all the Greek that Goldsmith knew, and all the Greek in all the world, would have meant nothing and done nothing for him. But there is and will be many another who finds in Greek wisdom and sweet Hellenic speech something which he needs must have, and lacking which he would be poor indeed: something which is as a staff in his hand, a light upon his path, a lantern to his feet.

In this workaday world we may still easily possess ourselves, as Gibbon says the subjects of the Byzantine Throne, even in their lowest servitude and depression, were still possessed, 'of a golden key that could unlock the treasures of antiquity, of a musical and prolific language that gives a soul to the objects of sense, and a body to the abstractions of philosophy'.

Our very lives seem prolonged by the recollection of antiquity; for, as Cicero says, not to know what has been transacted in former times is to continue always a child. I borrow the citation from Dr. Johnson, who reminds us also of a saying of Aristotle himself, that as students we ought first to examine and understand what has been written by the ancients, and then cast our eyes round upon the world. And Johnson prefaces both quotations by another:

Tibi res antiquae laudis et artis ingredior, sanctos ausus recludere fontes.

But now I, who have dared to draw my tiny draft from Aristotle's great well, seem after all to be seeking an excuse, seeking it in example and precept. Precept, at least, I know to be of no avail. My father spent all the many days of his life in the study of Greek; you might suppose it was for Wisdom's sake,--but my father was a modest man. The fact is, he did it for a simpler reason still, a very curious reason, to be whispered rather than told: he did it _for love_.

Nigh forty years ago, I first stepped out on the east-windy streets of a certain lean and hungry town (lean, I mean, as regards scholarship) where it was to be my lot to spend thereafter many and many a year. And the very first thing I saw there was an inscription over a very humble doorway, '_Hic mecum habitant Dante, Cervantes, Molière_'. It was the home of a poor schoolmaster, who as a teacher of languages eked out the scanty profits of his school. I was not a little comforted by the announcement. So the poor scholar, looking on the ragged regiment of his few books, is helped, consoled, exalted by the reflection: _Hic mecum habitant ... Homerus, Plato, Aristoteles_. And were one in a moment of inadvertence to inquire of him why he occupied himself with Greek, he might perchance stammer (like Dominie Sampson) an almost inarticulate reply; but more probably he would be stricken speechless by the enormous outrage of the request, and the reason of his devotion would be hidden from the questioner for ever.

D'ARCY WENTWORTH THOMPSON.

BIOLOGY

_Before Aristotle_

What is science? It is a question that cannot be answered easily, nor perhaps answered at all. None of the definitions seem to cover the field exactly; they are either too wide or too narrow. But we can see science in its growth and we can say that being a process it can exist only as growth. Where does the science of biology begin? Again we cannot say, but we can watch its evolution and its progress. Among the Greeks the accurate observation of living forms, which is at least one of the essentials of biological science, goes back very far. The word _Biology_, used in our sense, would, it is true, have been an impossibility among them, for _bios_ refers to the life of man and could not be applied, except in a strained or metaphorical sense, to that of other living things.[6] But the _ideas_ we associate with the word are clearly developed in Greek philosophy and the foundations of biology are of great antiquity.

[6] The word _Biology_ was introduced by Gottfried Reinhold Treviranus (1776-1837) in his _Biologie oder die Philosophie der lebenden Natur_, 6 vols., Göttingen, 1802-22, and was adopted by J.-B. de Lamarck (1744-1829) in his _Hydrogéologie_, Paris, 1802. It is probable that the first English use of the word in its modern sense is by Sir William Lawrence (1783-1867) in his work _On the Physiology, Zoology, and Natural History of Man_, London, 1819; there are earlier English uses of the word, however, contrasted with _biography_.

The Greek people had many roots, racial, cultural, and spiritual, and from them all they inherited various powers and qualities and derived various ideas and traditions. The most suggestive source for our purpose is that of the Minoan race whom they dispossessed and whose lands they occupied. That highly gifted people exhibited in all stages of its development a marvellous power of graphically representing animal forms, of which the famous Cretan friezes, Vaphio cups (Fig. 5), and Mycenean lions provide well-known examples. It is difficult not to believe that the Minoan element, entering into the mosaic of peoples that we call the Greeks, was in part at least responsible for the like graphic power developed in the Hellenic world, though little contact has yet been demonstrated between Minoan and archaic Greek Art.

For the earliest biological achievements of Greek peoples we have to rely largely on information gleaned from artistic remains. It is true that we have a few fragments of the works of both Ionian and Italo-Sicilian philosophers, and in them we read of theoretical speculation as to the nature of life and of the soul, and we can thus form some idea of the first attempts of such workers as Alcmaeon of Croton (_c._ 500 B. C.) to lay bare the structure of animals by dissection.[7] The pharmacopœia also of some of the earliest works of the Hippocratic collection betrays considerable knowledge of both native and foreign plants.[8] Moreover, scattered through the pages of Herodotus and other early writers is a good deal of casual information concerning animals and plants, though such material is second-hand and gives us little information concerning the habit of exact observation that is the necessary basis of science.

[7] The remains of Alcmaeon are given in H. Diel's _Die Fragmente der Vorsokratiker_, Berlin, 1903, p. 103. Alcmaeon is considered in the companion chapter on _Greek Medicine_.

[8] Especially the περι γυναικειης φυσιος {peri gynaikeiês physios}, _On the nature of woman_, and the περι γυναικειων {peri gynaikeiôn}, _On the diseases of women_.

Something more is, however, revealed by early Greek Art. We are in possession of a series of vases of the seventh and sixth centuries before the Christian era showing a closeness of observation of animal forms that tells of a people awake to the study of nature. We have thus portrayed for us a number of animals--plants seldom or never appear--and among the best rendered are wild creatures: we see antelopes quietly feeding or startled at a sound, birds flying or picking worms from the ground, fallow deer forcing their way through thickets, browsing peacefully, or galloping away, boars facing the hounds and dogs chasing hares, wild cattle forming their defensive circle, hawks seizing their prey. Many of these exhibit minutely accurate observation. The very direction of the hairs on the animals' coats has sometimes been closely studied, and often the muscles are well rendered. In some cases even the dentition has been found accurately portrayed, as in a sixth-century representation on an Ionian vase of a lioness--an animal then very rare on the Eastern Mediterranean littoral, but still known in Babylonia, Syria, and Asia Minor. The details of the work show that the artist must have examined the animal in captivity (Figs. 1 and 2).

[Illustration: FIG. 1. Lioness and young from an Ionian vase of the sixth century B. C. found at Caere in Southern Etruria (Louvre, Salle E, No. 298), from _Le Dessin des Animaux en Grèce d'après les vases peints_, by J. Morin, Paris (Renouard), 1911. The animal is drawing itself up to attack its hunters. The scanty mane, the form of the paws, the udders, and the dentition are all heavily though accurately represented.]

[Illustration: FIG. 2. A, Jaw bones of lion; B, head of lioness from Caere vase (Fig. 1), after Morin. Note the careful way in which the artist has distinguished the molar from the cutting teeth.]

Animal paintings of this order are found scattered over the Greek world with special centres or schools in such places as Cyprus, Boeotia, or Chalcis. The very name for a painter in Greek, _zoographos_, recalls the attention paid to living forms. By the fifth century, in painting them as in other departments of Art, the supremacy of Attica had asserted itself, and there are many beautiful Attic vase-paintings of animals to place by the side of the magnificent horses' heads of the Parthenon (Fig. 6). In Attica, too, was early developed a characteristic and closely accurate type of representation of marine forms, and this attained a wider vogue in Southern Italy in the fourth century. From the latter period a number of dishes and vases have come down to us bearing a large variety of fish forms, portrayed with an exactness that is interesting in view of the attention to marine creatures in the surviving literature of Aristotelian origin (Fig. 3).

[Illustration: FIG. 3. Paintings of fish on plates. Italo-Greek work of the fourth century B. C. From Morin.

A. Sargus vulgaris. B. Crenilabrus mediterraneus. C. Uranoscopus scaber?]

These artistic products are more than a mere reflex of the daily life of the people. The habits and positions of animals are observed by the hunter, as are the forms and colours of fish by the fisherman; but the methods of huntsman and fisher do not account for the accurate portrayal of a lion's dentition, the correct numbering of a fish's scales or the close study of the lie of the feathers on the head, and the pads on the feet, of a bird of prey (Fig. 4). With observations such as these we are in the presence of something worthy of the name _Biology_. Though but little literature on that topic earlier than the writings of Aristotle has come down to us, yet both the character of his writings and such paintings and pictures as these, suggest the existence of a strong interest and a wide literature, biological in the modern sense, antecedent to the fourth century.

[Illustration: FIG. 4. Head and talons of the Sea-eagle, _Haliaëtus albicilla_:

A, From an Ionic vase of the sixth century B. C. B, Drawn from the object.

From Morin.]

Greek science, however, exhibits throughout its history a peculiar characteristic differentiating it from the modern scientific standpoint. Most of the work of the Greek scientist was done in relation to man. Nature interested him mainly in relation to himself. The Greek scientific and philosophic world was an anthropocentric world, and this comes out in the overwhelming mass of medical as distinct from biological writings that have come down to us. Such, too, is the sentiment expressed by the poets in their descriptions of the animal creation:

Many wonders there be, but naught more wondrous than man:

* * * * *

The light-witted birds of the air, the beasts of the weald and the wood He traps with his woven snare, and the brood of the briny flood. Master of cunning he: the savage bull, and the hart Who roams the mountain free, are tamed by his infinite art. And the shaggy rough-maned steed is broken to bear the bit.

Sophocles, _Antigone_, verses 342 ff.

(Translation of F. Storr.)

It is thus not surprising that our first systematic treatment of animals is in a practical medical work, the περι διαιτης {peri diaitês}, _On diet_, of the Hippocratic Collection. This very peculiar treatise dates from the later part of the fifth century. It is strongly under the influence of Heracleitus (_c._ 540-475) and contains many points of view which reappear in later philosophy. All animals, according to it, are formed of fire and water, nothing is born and nothing dies, but there is a perpetual and eternal revolution of things, so that change itself is the only reality. Man's nature is but a parallel to that of the universal nature, and the arts of man are but an imitation or reflex of the natural arts or, again, of the bodily functions. The soul, a mixture of water and fire, consumes itself in infancy and old age, and increases during adult life. Here, too, we meet with that singular doctrine, not without bearing on the course of later biological thought, that in the foetus all parts are formed simultaneously. On the proportion of fire and water in the body all depends, sex, temper, temperament, intellect. Such speculative ideas separate this book from the sober method of the more typical Hippocratic medical works with which indeed it has little in common.

After having discussed these theoretical matters the work turns to its own practical concerns, and in the course of setting out the natures of foods gives in effect a rough classification of animals. These are set forth in groups, and from among the larger groups only the reptiles and insects are missing. The list has been described, perhaps hardly with justification, as the _Coan classificatory system_. We have here, indeed, no _system_ in the sense in which that word is now applied to the animal kingdom, but we have yet some sort of definite arrangement of animals according to their supposed natures. The passage opens with mammals, which are divided into domesticated and wild, the latter being mentioned in order according to size, next follow the land-birds, then the water-fowl, and then the fishes. These fish are divided into (1) the haunters of the shore, (2) the free-swimming forms, (3) the cartilaginous fishes or Selachii, which are not so named but are placed together, (4) the mud-loving forms, and (5) the fresh-water fish. Finally come invertebrates arranged in some sort of order according to their structure. The characteristic feature of the 'classification' is the separation of the fish from the remaining vertebrates and of the invertebrates from both. Of the fifty animals named no less than twenty are fish, about a fifth of the number studied by Aristotle, but we must remember that here only edible species are mentioned. The existence of the work shows at least that in the fifth century there was already a close and accurate study of animal forms, a study that may justly be called scientific. The predominance of fish and their classification in greater detail than the other groups is not an unexpected feature. The Mediterranean is especially rich in these forms, the Greeks were a maritime people, and Greek literature is full of imagery drawn from the fisher's craft. From Minoan to Byzantine times the variety, beauty, and colour of fish made a deep impression on Greek minds as reflected in their art.

Much more important, however, for subsequent biological development than such observations on the nature and habits of animals, is the service that the Hippocratic physicians rendered to Anatomy and to Physiology, departments in which the structure of man and of the domesticated animals stands apart from that of the rest of the animal kingdom. It is with the nature and constitution of man that most of the surviving early biological writings are concerned, and in these departments are unmistakable tendencies towards systematic arrangement of the material. Thus we have division and description of the body in sevens from the periphery to the centre and from the vertex to the sole of the foot,[9] or a division into four regions or zones.[10] The teaching concerning the four elements and four humours too became of great importance and some of it was later adopted by Aristotle. We also meet numerous mechanical explanations of bodily structures, comparisons between anatomical conditions encountered in related animals, experiments on living creatures,[11] systematic incubation of hen's eggs for the study of their development, parallels drawn between the development of plants and of human and animal embryos, theories of generation, among which is that which was afterwards called 'pangenesis'--discussion of the survival of the stronger over the weaker--almost our survival of the fittest--and a theory of inheritance of acquired characters.[12] All these things show not only extensive knowledge but also an attempt to apply such knowledge to human needs. When we consider how even in later centuries biology was linked with medicine, and how powerful and fundamental was the influence of the Hippocratic writings, not only on their immediate successors in antiquity, but also on the Middle Ages and right into the nineteenth century, we shall recognize the significance of these developments.

[9] περι ἑβδομαδων {peri hebdomadôn}. The Greek text is lost. We have, however, an early and barbarous Latin translation, and there has recently been printed an Arabic commentary. G. Bergstrasser, _Pseudogaleni in Hippocratis de septimanis commentarium ab Hunnino Q. F. arabice versum_, Leipzig, 1914.

[10] περι νουσων δ {peri nousôn d}.

[11] περι καρδιης {peri kardiês}.

[12] Especially in the περι γονης {peri gonês}.

[Illustration: Fig. 5. MINOAN GOLD CUP. SIXTEENTH CENTURY B. C.]

[Illustration: Fig. 6. HORSE'S HEAD. FROM PARTHENON. 440 B. C.]

Such was the character of biological thought within the fifth century, and a generation inspired by this movement produced some noteworthy works in the period which immediately followed. In the treatise περι τροφης {peri trophês}, _On nourishment_, which may perhaps be dated about 400 B. C., we learn of the pulse for the first time in Greek medical literature, and read of a physiological system which lasted until the time of Harvey, with the arteries arising from the heart and the veins from the liver. Of about the same date is a work περι καρδιης {peri kardiês}, _On the heart_, which describes the ventricles as well as the great vessels and their valves, and compares the heart of animals with that of man.

A little later, perhaps 390 B. C., is the treatise περι σαρκων {peri sarkôn}, _On muscles_, which contains much more than its title suggests. It has the old system of sevens and, inspired perhaps by the philosophy of Heracleitus (_c._ 540-475), describes the heart as sending air, fire, and movement to the different parts of the body through the vessels which are themselves constantly in movement. The infant in its mother's womb is believed to draw in air and fire through its mouth and to eat _in utero_. The action of the air on the blood is compared to its action on fire. In contrast to some of the other Hippocratic treatises the central nervous system is in the background; much attention, however, is given to the special senses. The brain resounds during audition. The olfactory nerves are hollow, lead to the brain, and, convey volatile substances to it which cause it to secrete mucus. The eyes also have been examined, and their coats and humours roughly described; an allusion, the first in literature, is perhaps made to the crystalline lens, and the eyes of animals are compared with those of man. There is evidence not only of dissection but of experiment, and in efforts to compare the resistance of various tissues to such processes as boiling, we may see the small beginning of chemical physiology.

An abler work than any of these, but exhibiting less power of observation is a treatise, περι γονης {peri gonês}, _On generation_, that may perhaps be dated about 380 B. C.[13] It exhibits a writer of much philosophic power, very anxious for physiological explanations, but hampered by ignorance of physics. He has, in fact, the weaknesses and in a minor degree the strength of his successor Aristotle, of whose great work on generation he gives us a fore-taste. He sets forth in considerable detail a doctrine of pangenesis, not wholly unlike that of Darwin. In order to explain the phenomena of inheritance he supposes that vessels reach the seed, carrying with them samples from all parts of the body. He believes that channels pass from all the organs to the brain and then to the spinal marrow (or to the marrow direct), thence to the kidneys and on to the genital organs; he believes, too, that he knows the actual location of one such channel, for he observes, wrongly, that incision behind the ears, by interrupting the passage, leads to impotence. As an outcome of this theory he is prepared to accept inheritance of acquired characters. The embryo develops and breathes by material transmitted from the mother through the umbilical cord. We encounter here also a very detailed description of a specimen of exfoliated _membrana mucosa uteri_ which our author mistakes for an embryo, but his remarks at least exhibit the most eager curiosity.[14]

[13] The three works περι γονης {peri gonês}, περι φυσιος παιδιου {peri physios paidiou}, περι νουσων δ {peri nousôn d}, _On generation_, _on the nature of the embryo_, _on diseases, book IV_, form really one treatise on generation.

[14] περι φυσιος παιδιου {peri physios paidiou}, _On the nature of the embryo_, § 13. The same experience is described in the περι σαρκων {peri sarkôn}, _On the muscles_.

The author of this work on generation is thus a 'biologist' in the modern sense, and among the passages exhibiting him in this light is his comparison of the human embryo with the chick. 'The embryo is in a membrane in the centre of which is the navel through which it draws and gives its breath, and the membranes arise from the umbilical cord.... The structure of the child you will find from first to last as I have already described.... If you wish, try this experiment: take twenty or more eggs and let them be incubated by two or more hens. Then each day from the second to that of hatching remove an egg, break it, and examine it. You will find exactly as I say, for the nature of the bird can be likened to that of man. The membranes [you will see] proceed from the umbilical cord, and all that I have said on the subject of the infant you will find in a bird's egg, and one who has made these observations will be surprised to find an umbilical cord in a bird's egg.'[15]

[15] περι φυσιος παιδιου {peri physios paidiou}, _On the nature of the embryo_, § 29.

The same interest that he exhibits for the development of man and animals he shows also for plants.

'A seed laid in the ground fills itself with the juices there contained, for the soil contains in itself juices of every nature for the nourishment of plants. Thus filled with juice the seed is distended and swells, and thereby the power (= faculty ἡ δυναμις {hê dynamis}) diffused in the seed is compressed by pneuma and juice, and bursting the seed becomes the first leaves. But a time comes when these leaves can no longer get nourished from the juices in the seed. Then the seed and the leaves erupt below, for urged by the leaves the seed sends down that part of its power which is yet concentrated within it and so the roots are produced as an extension of the leaves. When at last the plant is well rooted below and is drawing its nutriment from the earth, then the whole grain disappears, being absorbed, save for the husk, which is the most solid part; and even that, decomposing in the earth, ultimately becomes invisible. In time some of the leaves put forth branches. The plant being thus produced by humidity from the seed is still soft and moist. Growing actively both above and below, it cannot as yet bear fruit, for it has not the quality of force and reserve (δυναμις ισχυρη και πιαρα {dynamis ischyrê kai piara}) from which a seed can be precipitated. But when, with time, the plant becomes firmer and better rooted, it develops veins as passages both upwards and downwards, and it draws from the soil not only water but more abundantly also substances that are denser and fatter. Warmed, too, by the sun, these act as a ferment to the extremities and give rise to fruit after its kind. The fruit thus develops much from little, for every plant draws from the earth a power more abundant than that with which it started, and the fermentation takes place not at one place but at many.'[16]

[16] περι φυσιος παιδιου {peri physios paidiou}, _On the nature of the embryo_, § 22.

Nor does our author hesitate to draw an analogy between the plant and the mammalian embryo. 'In the same way the infant lives within its mother's womb and in a state corresponding to the health of the mother ... and you will find a complete similitude between the products of the soil and the products of the womb.'

The early Greek literature is so scantily provided with illustrations drawn from botanical study, that it is worth considering the remarkable comparison of generation of plants from cuttings and from seeds in the same work.

'As regards plants generated from cuttings ... that part of a branch where it was cut from a tree is placed in the earth and there rootlets are sent out. This is how it happens: The part of the plant within the soil draws up juices, swells, and develops a pneuma (πνευμα ισχει {pneuma ischei}), but not so the part without. The pneuma and the juice concentrate the power of the plant below so that it becomes denser. Then the lower end erupts and gives forth tender roots. Then the plant, taking from below, draws juices from the roots and transmits them to the part above the soil which thus also swells and develops pneuma; thus the power from being diffused in the plant becomes concentrated and budding, gives forth leaves.... Cuttings, then, differ from seeds. With a seed the leaves are borne first, then the roots are sent down; with a cutting the roots form first and then the leaves.'[17]

[17] Ibid. § 23.

But with these works of the early part of the fourth century the first stage of Greek biology reaches its finest development. Later Hippocratic treatises which deal with physiological topics are on a lower plane, and we must seek some external cause for the failure. Nor have we far to seek. This period saw the rise of a movement that had the most profound influence on every department of thought. We see the advent into the Greek world of a great intellectual movement as a result of which the department of philosophy that dealt with nature receded before Ethics. Of that intellectual revolution--perhaps the greatest the world has seen--Athens was the site and Socrates (470-399) the protagonist. With the movement itself and its characteristic fruit we are not concerned. But the great successor and pupil of its founder gives us in the _Timaeus_ a picture of the depth to which natural science can be degraded in the effort to give a specific teleological meaning to all parts of the visible Universe. The book and the picture which it draws, dark and repulsive to the mind trained in modern scientific method, enthralled the imagination of a large part of mankind for wellnigh two thousand years. Organic nature appears in this work of Plato (427-347) as the degeneration of man whom the Creator has made most perfect. The school that held this view ultimately decayed as a result of its failure to advance positive knowledge. As the centuries went by its views became further and further divorced from phenomena, and the bizarre developments of later Neoplatonism stand to this day as a warning against any system which shall neglect the investigation of nature. But in its decay Platonism dragged science down and destroyed by neglect nearly all earlier biological material. Mathematics, not being a phenomenal study, suited better the Neoplatonic mood and continued to advance, carrying astronomy with it for a while--astronomy that affected the life of man and that soon became the handmaid of astrology; medicine, too, that determined the conditions of man's life was also cherished, though often mistakenly, but pure science was doomed.

But though the ethical view of nature overwhelmed science in the end, the advent of the mighty figure of Aristotle (384-322) stayed the tide for a time. Yet the writer on Greek Biology remains at a disadvantage in contrast with the Historian of Greek Mathematics, of Greek Astronomy, or of Greek Medicine, in the scantiness of the materials for presenting an account of the development of his studies before Aristotle. The huge form of that magnificent naturalist completely overshadows Greek as it does much of later Biology.

CHARLES SINGER.

_After Aristotle_

All Aristotle's surviving biological works refer primarily to the animal creation. His work on plants is lost or rather has survived as the merest corrupted fragment. We are fortunate, however, in the possession of a couple of complete works by his pupil and successor Theophrastus (372-287), which may not only be taken to represent the Aristotelian attitude towards the plant world, but also give us an inkling of the general state of biological science in the generation which succeeded the master.

[Illustration: Fig. 7. ARISTOTLE From HERCULANEUM Probably work of fourth century B. C.]

These treatises of Theophrastus are in many respects the most complete and orderly of all ancient biological works that have reached our time. They give an idea of the kind of interest that the working scientist of that day could develop when inspired rather by the genius of a great teacher than by the power of his own thoughts. Theophrastus is a pedestrian where Aristotle is a creature of wings, he is in a relation to the master of the same order that the morphologists of the second half of the nineteenth century were to Darwin. For a couple of generations after the appearance of the _Origin of Species_ in 1859 the industry and ability of naturalists all over the world were occupied in working out in detail the structure and mode of life of living things on the basis of the Evolutionary philosophy. Nearly all the work on morphology and much of that on physiology since his time might be treated as a commentary on the works of Darwin. These volumes of Theophrastus give the same impression. They represent the remains--alas, almost the only biological remains--of a school working under the impulse of a great idea and spurred by the memory of a great teacher. As such they afford a parallel to much scientific work of our own day, produced by men without genius save that provided by a vision and a hope and an ideal. Of such men it is impossible to write as of Aristotle. Their lives are summed up by their actual achievement, and since Theophrastus is an orderly writer whose works have descended to us in good state, he is a very suitable instance of the actual standard of achievement of ancient biology. 'Without vision the people perish' and the very breath of life of science is drawn, and can only be drawn, from that very small band of prophets who from time to time, during the ages, have provided the great generalizations and the great ideals. In this light let us examine the work of Theophrastus.

In the absence of any adequate system of classification, almost all botany until the seventeenth century consisted mainly of descriptions of species. To describe accurately a leaf or a root in the language in ordinary use would often take pages. Modern botanists have invented an elaborate terminology which, however hideous to eye and ear, has the crowning merit of helping to abbreviate scientific literature. Botanical writers previous to the seventeenth century were substantially without this special mode of expression. It is partly to this lack that we owe the persistent attempts throughout the centuries to represent plants pictorially in herbals, manuscript and printed, and thus the possibility of an adequate history of plant illustration.

Theophrastus seems to have felt acutely the need of botanical terms, and there are cases in which he seeks to give a special technical meaning to words in more or less current use. Among such words are _carpos_ = fruit, _pericarpion_ = seed vessel = pericarp, and _metra_, the word used by him for the central core of any stem whether formed of wood, pith, or other substance. It is from the usage of Theophrastus that the exact definition of fruit and pericarp has come down to us.[18] We may easily discern also the purpose for which he introduces into botany the term _metra_, a word meaning primarily the _womb_, and the vacancy in the Greek language which it was made to fill. '_Metra_,' he says, 'is that which is in the middle of the wood, being third in order from the bark and [thus] like to the marrow in bones. Some call it the _heart_ (καρδιαν {kardian}), others the _inside_ (εντεριωνην {enteriônên}), yet others call only the innermost part of the metra itself the heart, while others again call this _marrow_.'[19] He is thus inventing a word to cover all the different kinds of core and importing it from another study. This is the method of modern scientific nomenclature which hardly existed for botanists even as late as the sixteenth century of our era. The real foundations of our modern nomenclature were laid in the later sixteenth and in the seventeenth century by Cesalpino and Joachim Jung.

[18] It is possible that Theophrastus derived the word pericarp from Aristotle. Cp. _De anima_, ii. 1, 412 b 2. In the passage το φυλλον περικαρπιου σκεπασμα, το δε περικαρπιον καρπου {to phyllon perikarpiou skepasma, to de perikarpion karpou}, in the _De anima_ the word does not, however, seem to have the full technical force that Theophrastus gives to it.

[19] _Historia plantarum_, i. 2, vi.

Theophrastus understood the value of developmental study, a conception derived from his master. 'A plant', he says, 'has power of germination in all its parts, for it has life in them all, wherefore we should regard them not for what they are but for what they are becoming.'[20] The various modes of plant reproduction are correctly distinguished in a way that passes beyond the only surviving earlier treatise that deals in detail with the subject, the Hippocratic work _On generation_. 'The manner of generation of trees and plants are these: spontaneous, from a seed, from a root, from a piece torn off, from a branch or twig, from the trunk itself, or from pieces of the wood cut up small.'[21] The marvel of germination must have awakened admiration from a very early date. We have already seen it occupying a more ancient author, and it had also been one of the chief preoccupations of Aristotle. It is thus not remarkable that the process should impress Theophrastus, who has left on record his views on the formation of the plant from the seed.

[20] _Ibid._ i. 1, iv.

[21] _Historia plantarum_, ii. 1, i.

'Some germinate, root and leaves, from the same point, some separately from either end of the seed. Thus wheat, barley, spelt, and all such cereals [germinate] from either end, corresponding to the position [of the seed] in the ear, the root from the stout lower part, the shoot from the upper; but the two, root and stem, form a single continuous whole. The bean and other leguminous plants are not so, but in them root and stem are from the same point, namely, their place of attachment to the pod, where, it is plain, they have their origin. In some cases there is a process, as in beans, chick peas, and especially lupines, from which the root grows downward, the leaf and stem upward.... In certain trees the bud first germinates within the seed, and, as it increases in size, the seeds split--all such seeds are, as it were, in two halves; again, all those of leguminous plants have plainly two lobes and are double--and then the root is immediately thrust out. But in cereals, the seeds being in one piece, this does not happen, but the root grows a little before [the shoot].

'Barley and wheat come up monophyllous, but peas, beans, and chick peas polyphyllous. All leguminous plants have a single woody root, from which grow slender side roots ... but wheat, barley, and the other cereals have numerous slender roots by which they are matted together.... There is a contrast between these two kinds; the leguminous plants have a single root and have many side-growths above from the [single] stem ... while the cereals have many roots and send up many shoots, but these have no side-shoots.'[22]

[22] _Historia plantarum_, viii. 1, i.

There can be no doubt that here is a piece of minute observation on the behaviour of germinating seeds. The distinction between dicotyledons and monocotyledons is accurately set forth, though the stress is laid not so much on the cotyledonous character of the seed as on the relation of root and shoot. In the dicotyledons root and shoot are represented as springing from the same point, and in monocotyledons from opposite poles in the seed.

No further effective work was done on the germinating seed until the invention of the microscope, and the appearance of the work of Highmore (1613-85),[23] and the much more searching investigations of Malpighi (1628-94)[24] and Grew (1641-1712)[25] after the middle of the seventeenth century. The observations of Theophrastus are, however, so accurate, so lucid, and so complete that they might well be used as legends for the plates of these writers two thousand years after him.

[23] Nathaniel Highmore, _A History of Generation_, London, 1651.

[24] Marcello Malpighi, _Anatome plantarum_, London, 1675.

[25] Nehemiah Grew, _Anatomy of Vegetables begun_, London, 1672.

Much has been written as to the knowledge of the sex of plants among the ancients. It may be stated that of the sexual elements of the flower no ancient writer had any clear idea. Nevertheless, sex is often attributed to plants, and the simile of the _Loves of Plants_ enters into works of the poets. Plants are frequently described as male and female in ancient biological writings also, and Pliny goes so far as to say that some students considered that all herbs and trees were sexual.[26] Yet when such passages can be tested it will be found that these so-called males and females are usually different species. In a few cases a sterile variety is described as the male and a fertile as the female. In a small residuum of cases diœcious plants or flowers are regarded as male and female, but with no real comprehension of the sexual nature of the flowers. There remain the palms, in which the knowledge of plant sex had advanced a trifle farther. 'With dates', says Theophrastus, 'the males should be brought to the females; for the males make the fruit persist and ripen, and this some call by analogy _to use the wild fig_ (ολυνθαζειν {olynthazein}).[27] The process is thus: when the male is in the flower they at once cut off the spathe with the flower and shake the bloom, with its flower and dust, over the fruit of the female, and, if it is thus treated, it retains the fruit and does not shed it.'[28] The fertilizing character of the spathe of the male date palm was familiar in Babylon from a very early date. It is recorded by Herodotus[29] and is represented by a frequent symbol on the Assyrian monuments.

[26] Pliny, _Naturalis historia_, xiii. 4.

[27] The curious word ολυνθαζειν {olynthazein}, here translated _to use the wild fig_, is from ολυνθος {olynthos}, a kind of wild fig which seldom ripens. The special meaning here given to the word is explained in another work of Theophrastus, _De causis plantarum_, ii. 9, xv. After describing caprification in figs, he says το δε επι των φοινικων συμβαινον ου ταυτον μεν, εχει δε τινα ὁμοιοτητα τουτω δι' ὁ καλουσιν ολυνθαζειν αυτους {to de epi tôn phoinikôn symbainon ou tauton men, echei de tina homoiotêta toutô di' ho kalousin olynthazein autous} 'The same thing is not done with dates, but something analogous to it, whence this is called ολυνθαζειν' {olynthazein'}.

[28] _Historia plantarum_, ii. 8, iv.

[29] Herodotus i. 193.

The comparison of the fertilization of the date palm to the use of the wild fig refers to the practice of Caprification. Theophrastus tells us that there are certain trees, the fig among them, which are apt to shed their fruit prematurely. To remedy this 'the device adopted is caprification. Gall insects come out of the wild figs which are hanging there, eat the tops of the cultivated figs, and so make them swell'.[30] These gall-insects 'are engendered from the seeds'.[31] Theophrastus distinguished between the process as applied to the fig and the date, observing that 'in both [fig and date] the male aids the female--for they call the fruit-bearing [palm] _female_--but whilst in the one there is a union of the two sexes, in the other things are different'.[32]

[30] _Historia plantarum_, ii. 8, i.

[31] _Ibid._ ii. 8, ii.

[32] _Historia plantarum_, ii. 8, iv.

Theophrastus was not very successful in distinguishing the nature of the primary elements of plants, though he was able to separate root, stem, leaf, stipule, and flower on morphological as well as to a limited extent on physiological grounds. For the root he adopts the familiar definition, the only one possible before the rise of chemistry, that it 'is that by which the plant draws up nourishment',[33] a description that applies to the account given by the pre-Aristotelian author of the work περι γονης {peri gonês}, _On generation_. But Theophrastus shows by many examples that he is capable of following out morphological homologies. Thus he knows that the ivy regularly puts forth roots from the shoots between the leaves, by means of which it gets hold of trees and walls,[34] that the mistletoe will not sprout except on the bark of living trees into which it strikes its roots, and that the very peculiar formation of the mangrove tree is to be explained by the fact that 'this plant sends out roots from the shoots till it has hold on the ground and roots again: and so there comes to be a continuous circle of roots round the tree, not connected with the main stem, but at a distance from it'.[35] He does not succeed, however, in distinguishing the real nature of such structures as bulbs, rhizomes, and tubers, but regards them all as roots. Nor is he more successful in his discussion of the nature of stems. As to leaves, he is more definite and satisfactory, though wholly in the dark as to their function; he is quite clear that the pinnate leaf of the rowan tree, for instance, is a leaf and not a branch.

[33] _Ibid._ i. 1, ix.

[34] _Ibid._ iii. 18, x.

[35] _De causis plantarum_, ii. 23.

Notwithstanding his lack of insight as to the nature of sex in flowers, he attains to an approximately correct idea of the relation of flower and fruit. Some plants, he says, 'have [the flower] around the fruit itself as vine and olive; [the flowers] of the latter, when they drop, look as though they had a hole through them, and this is taken for a sign that it has blossomed well; for if [the flower] is burnt up or sodden, the fruit falls with it, and so it does not become pierced. Most flowers have the fruit case in the middle, or it may be the flower is on the top of the pericarp as in pomegranate, apple, pear, plum, and myrtle ... for these have their seeds below the flower.... In some cases again the flower is on top of the seeds themselves as in ... all thistle-like plants'.[36] Thus Theophrastus has succeeded in distinguishing between the hypogynous, perigynous, and epigynous types of flower, and has almost come to regard its relation to the fruit as the essential floral element.

[36] _Historia plantarum_, i. 13, iii.

[Illustration: Fig. 8. THEOPHRASTUS From VILLA ALBANI Copy (second century A. D.?) of earlier work]

Theophrastus has a perfectly clear idea of plant distribution as dependent on soil and climate, and at times seems to be on the point of passing from a statement of climatic distribution into one of real geographical regions. The general question of plant distribution long remained at, if it did not recede from, the position where he left it. The usefulness of the manuscript and early printed herbals in the West was for centuries marred by the retention of plant descriptions prepared for the Greek East and Latin South, and these works were saved from complete ineffectiveness only by an occasional appeal to nature.

With the death of Theophrastus about 287 B. C. pure biological science substantially disappears from the Greek world, and we get the same type of deterioration that is later encountered in other scientific departments. Science ceases to have the motive of the desire to know, and becomes an applied study, subservient to the practical arts. It is an attitude from which in the end applied science itself must suffer also. Yet the centuries that follow were not without biological writers of very great ability. In the medical school of Alexandria anatomy and physiology became placed on a firm basis from about 300 B. C., but always in the position subordinate to medicine that they have since occupied. Two great names of that school, Herophilus and Erasistratus, we must consider elsewhere.[37] Their works have disappeared and we have the merest fragments of them. In the last pre-Christian and the first two post-Christian centuries, however, there were several writers, portions of whose works have survived and are of great biological importance. Among them we include Crateuas, a botanical writer and illustrator, who greatly developed, if he did not actually introduce, the method of representing plants systematically by illustration rather than by description. This method, important still, was even more important when there was no proper system of botanical nomenclature. Crateuas by his paintings of plants, copies of which have not improbably descended to our time, began a tradition which, fixed about the fifth century, remained almost rigid until the re-discovery of nature in the sixteenth. He was physician to Mithridates VI Eupator (120-63 B. C.), but his work was well known and appreciated at Rome, which became the place of resort for Greek talent.[38]

[37] See the companion chapter on _Greek Medicine_.

[38] The surviving fragments of the works of Crateuas have recently been printed by M. Wellmann as an appendix to the text of Dioscorides, _De materia medica_, 3 vols., Berlin, 1906-17, iii. pp. 144-6. The source and fate of his plant drawings are discussed in the same author's _Krateuas_, Berlin, 1897.

Celsus, who flourished about 20 B. C., wrote an excellent work on medicine, but gives all too little glimpse of anatomy and physiology. Rufus of Ephesus, however, in the next century practised dissection of apes and other animals. He described the decussation of the optic nerves and the capsule of the crystalline lens, and gave the first clear description that has survived of the structure of the eye. He regarded the nerves as originating from the brain, and distinguished between nerves of motion and of sensation. He described the oviduct of the sheep and rightly held that life was possible without the spleen.

The second Christian century brings us two writers who, while scientifically inconsiderable, acted as the main carriers of such tradition of Greek biology as reached the Middle Ages, Pliny and Dioscorides. Pliny (A. D. 23-79), though a Latin, owes almost everything of value in his encyclopaedia to Greek writings. In his _Natural History_ we have a collection of current views on the nature, origin, and uses of plants and animals such as we might expect from an intelligent, industrious, and honest member of the landed class who was devoid of critical or special scientific skill. Scientifically the work is contemptible, but it demands mention in any study of the legacy of Greece, since it was, for centuries, a main conduit of the ancient teaching and observations on natural history. Read throughout the ages, alike in the darkest as in the more enlightened periods, copied and recopied, translated, commented on, extracted and abridged, a large part of Pliny's work has gradually passed into folk-keeping, so that through its agency the gipsy fortune-teller of to-day is still reciting garbled versions of the formulae of Aristotle and Hippocrates of two and a half millennia ago.

The fate of Dioscorides (flourished A. D. 60) has been not dissimilar. His work _On Materia Medica_ consists of a series of short accounts of plants, arranged almost without reference to the nature of the plants themselves, but quite invaluable for its terse and striking descriptions which often include habits and habitats. Its history has shown it to be one of the most influential botanical treatises ever penned. It provided most of the little botanical knowledge that reached the Middle Ages. It furnished the chief stimulus to botanical research at the time of the Renaissance. It has decided the general form of every modern pharmacopœia. It has practically determined modern plant nomenclature both popular and scientific.

Translated into nearly every language from Anglo-Saxon and Bohemian to Arabic and Hebrew, appearing both abstracted and in full in innumerable beautifully illuminated manuscripts, some of which are still among the fairest treasures of the great national libraries, Dioscorides, the drug-monger, appealed to scholasticized minds for centuries. The frequency with which fragments of him are encountered in papyri shows how popular his work was in Egypt in the third and fourth centuries. One of the earliest datable Greek codices in existence is a glorious volume of Dioscorides written in capitals,[39] thought worthy to form a wedding gift for a lady who was the daughter of one Roman emperor and the betrothed of a second.[40] The illustrations of this fifth-century manuscript are a very valuable monument for the history of art and the chief adornment of what was once the Royal Library at Vienna[41] (figs. 9-10). Illustrated Latin translations of Dioscorides were in use in the time of Cassiodorus (490-585). A work based on it, similarly illustrated, but bearing the name of Apuleius, is among the most frequent of mediaeval botanical documents and the earliest surviving specimen is contemporary with Cassiodorus himself.[42] After the revival of learning Dioscorides continued to attract an immense amount of philological and botanical ability, and scores of editions of his works, many of them nobly illustrated, poured out of the presses of the sixteenth and seventeenth centuries.

[Illustration: Fig. 9 ΣΟΓΚΟΣ ΤΡΥΦΕΡΟΣ {SOGKOS TRYPHEROS} = _Crepis paludosa_, _Mœn._]

[Illustration: Fig. 10 ΓΕΡΑΝΙΟΝ {GERANION} = _Geranium pyrenaicum_, _L._

Fifth-century drawings from JULIANA ANICIA M.S., copied from originals of first century B. C. (?)]

[39] The manuscript in question is Med. Graec. 1 at what was the Royal Library at Vienna. It is known as the _Constantinopolitanus_. After the war it was taken to St. Mark's at Venice, but either has been or is about to be restored to Vienna. A facsimile of this grand manuscript was published by Sijthoff, Leyden, 1906.

[40] The lady in question was Juliana Anicia, daughter of Anicius Olybrius, Emperor of the West in 472, and his wife Placidia, daughter of Valentinian III. Juliana was betrothed in 479 by the Eastern Emperor Zeno to Theodoric the Ostrogoth, but was married, probably in 487 when the manuscript was presented to her, to Areobindus, a high military officer under the Byzantine Emperor Anastasius.

[41] The importance of this manuscript as well as the position of Dioscorides as medical botanist is discussed by Charles Singer in an article 'Greek Biology and the Rise of Modern Biology', _Studies in the History and Method of Science_, vol. ii, Oxford, 1921.

[42] This manuscript is at the University Library at Leyden, where it is numbered Voss Q 9.

But the greatest biologist of the late Greek period, and indeed one of the greatest biologists of all time, was Claudius Galen of Pergamon (A. D. 131-201). Galen devoted himself to medicine from an early age, and in his twenty-first year we hear of him studying anatomy at Smyrna under Pelops. With the object of extending his knowledge of drugs he early made long journeys to Asia Minor. Later he proceeded to Alexandria, where he improved his anatomical equipment, and here, he tells us, he examined a human skeleton. It is indeed probable that his direct practical acquaintance with human anatomy was limited to the skeleton and that dissection of the human body was no longer carried on at Alexandria in his time. Thus his physiology and anatomy had to be derived mainly from animal sources. He is the most voluminous of all ancient scientific writers and one of the most voluminous writers of antiquity in any department. We are not here concerned with the medical material which mainly fills these huge volumes, but only with the physiological views which not only prevailed in medicine until Harvey and after, but also governed for fifteen hundred years alike the scientific and the popular ideas on the nature and workings of the animal body, and have for centuries been embedded in our speech. A knowledge of these physiological views of Galen is necessary for any understanding of the history of biology and illuminates many literary allusions of the Middle Ages and Renaissance.

Between the foundation of the Alexandrian school and the time of Galen, medicine was divided among a great number of sects. Galen was an eclectic and took portions of his teaching from many of these schools, but he was also a naturalist of great ability and industry, and knew well the value of the experimental way. Yet he was a somewhat windy philosopher and, priding himself on his philosophic powers, did not hesitate to draw conclusions from evidence which was by no means always adequate. The physiological system that he thus succeeded in building up we may now briefly consider (fig. 11).

[Illustration: FIG. 11. Illustrating Galen's physiological teaching.]

The basic principle of life, in the Galenic physiology, is a _spirit_, _anima_ or _pneuma_, drawn from the general world-soul in the act of respiration. It enters the body through the _rough artery_ (τραχεια αρτηρια {tracheia artêria}, _arteria aspera_ of mediaeval notation), the organ known to our nomenclature as the trachea. From this trachea the pneuma passes to the lung and then, through the _vein-like artery_ (αρτηρια φλεβωδης {artêria phlebôdês}, _arteria venalis_ of mediaeval writers, the pulmonary vein of our nomenclature), to the left ventricle. Here it will be best to leave it for a moment and trace the vascular system along a different route.

Ingested food, passing down the alimentary tract, was absorbed as chyle from the intestine, collected by the portal vessel, and conveyed by it to the liver. That organ, the site of the innate heat in Galen's view, had the power of elaborating the chyle into venous blood and of imbuing it with a spirit or pneuma which is innate in all living substance, so long as it remains alive, the _natural spirits_ (πνευμα φυσικον {pneuma physikon}, _spiritus naturalis_ of the mediaevals). Charged with this, and also with the nutritive material derived from the food, the venous blood is distributed by the liver through the veins which arise from it in the same way as the arteries from the heart. These veins carry nourishment and _natural spirits_ to all parts of the body. _Iecur fons venarum_, the liver as the source of the veins, remained through the centuries the watchword of the Galenic physiology. The blood was held to ebb and flow continuously in the veins during life.

Now from the liver arose one great vessel, the hepatic vein, from division of which the others were held to come off as branches. Of these branches, one, our _common vena cava_, entered the right side of the heart. For the blood that it conveyed to the heart there were two fates possible. The greater part remained awhile in the ventricle, parting with its impurities and vapours, exhalations of the organs, which were carried off by the _artery-like vein_ (φλεπς αρτηριωδης {phleps artêriôdês}, the mediaeval _vena arterialis_, our pulmonary artery) to the lung and then exhaled to the outer air. These impurities and vapours gave its poisonous and suffocating character to the breath. Having parted thus with its impurities, the venous blood ebbed back again from the right ventricle into the venous system. But for a small fraction of the venous blood that entered the right ventricle another fate was reserved. This small fraction of venous blood, charged still with the _natural spirits_ derived from the liver, passed through minute channels in the septum between the ventricles and entered the left chamber. Arrived there, it encountered the external pneuma and became thereby elaborated into a higher form of spirit, the _vital spirits_ (πνευμα ζωτικον {pneuma zôtikon}, _spiritus vitalis_), which is distributed together with blood by the arterial system to various parts of the body. In the arterial system it also ebbed and flowed, and might be seen and felt to pulsate there.

But among the great arterial vessels that sent forth arterial blood thus charged with vital spirits were certain vessels which ascended to the brain. Before reaching that organ they divided up into minute channels, the _rete mirabile_ (πλεγμα μεγιστον θαυμα {plegma megiston thauma}), and passing into the brain became converted by the action of that organ into a yet higher type of spirits, the _animal spirits_ (πνευμα ψυχικον {pneuma psychikon}, _spiritus animalis_), an ethereal substance distributed to the various parts of the body by the structures known to-day as nerves, but believed then to be hollow channels. The three fundamental faculties (δυναμεις {dynameis}), the _natural_, the _vital_, and the _animal_, which brought into action the corresponding functions of the body, thus originated as an expression of the primal force or pneuma.

This physiology, we may emphasize, is not derived from an investigation of human anatomy. In the human brain there is no _rete mirabile_, though such an organ is found in the calf. In the human liver there is no _hepatic vein_, though such an organ is found in the dog. Dogs, calves, pigs, bears, and, above all, Barbary apes were freely dissected by Galen and were the creatures from which he derived his physiological ideas. Many of Galen's anatomical and physiological errors are due to his attributing to one creature the structures found in another, a fact that only very gradually dawned on the Renaissance anatomists.

The whole knowledge possessed by the world in the department of physiology from the third to the seventeenth century, nearly all the biological conceptions till the thirteenth, and most of the anatomy and much of the botany until the sixteenth century, all the ideas of the physical structure of living things throughout the Middle Ages, were contained in a small number of these works of Galen. The biological works of Aristotle and Theophrastus lingered precariously in a few rare manuscripts in the monasteries of the East; the total output of hundreds of years of Alexandrian and Pergamenian activities was utterly destroyed; the Ionian biological works, of which a sample has by a miracle survived, were forgotten; but these vast, windy, ill-arranged treatises of Galen lingered on. Translated into Latin, Syriac, Arabic, and Hebrew, they saturated the intellectual world of the Middle Ages. Commented on by later Greek writers, who were themselves in turn translated into the same list of languages, they were yet again served up under the names of such Greek writers as Oribasius, Paul of Aegina, or Alexander of Tralles.

What is the secret of the vitality of these Galenic biological conceptions? The answer can be given in four words. _Galen is a teleologist_; and a teleologist of a kind whose views happened to fit in with the prevailing theological attitude of the Middle Ages, whether Christian, Moslem, or Jewish. According to him everything which exists and displays activity in the human body originates in and is formed by an intelligent being and on an intelligent plan, so that the organ in structure and function is the result of that plan. 'It was the Creator's infinite wisdom which selected the best means to attain his beneficent ends, and it is a proof of His omnipotence that he created every good thing according to His design, and thereby fulfilled His will.'[43]

[43] A good instance of Galen's teleological point of view is afforded by his classical description of _the hand_ in the περι χρειας των εν ανθρωπου σωματι μοριων {peri chreias tôn en anthrôpou sômati moriôn}, _On the uses of the parts of the body of man_, i. 1. This passage is available in English in a tract by Thomas Bellott, London, 1840.

After Galen there is a thousand years of darkness, and biology ceases to have a history. The mind of the Dark Ages turned towards theology, and such remains of Neoplatonic philosophy as were absorbed into the religious system were little likely to be of aid to the scientific attitude. One department of positive knowledge must of course persist. Men still suffered from the infirmities of the flesh and still sought relief from them. But the books from which that advice was sought had nothing to do with general principles nor with knowledge as such. They were the most wretched of the treatises that still masqueraded under the names of Hippocrates and Galen, mostly mere formularies, antidotaries, or perhaps at best symptom lists. And, when the depression of the western intellect had passed its worst, there was still no biological material on which it could be nourished.

The prevailing interest of the barbarian world, at last beginning to settle into its heritage of antiquity, was with Logic. Of Aristotle there survived in Latin dress only the _Categories_ and the _De interpretatione_, the merciful legacy of Boethius, the last of the philosophers. Had a translation of Aristotle's _Historia animalium_ or _De generatione animalium_ survived, had a Latin version of the Hippocratic work _On generation_ or of the treatises of Theophrastus _On plants_ reached the earlier Middle Ages, the whole mental history of Europe might have been different and the rediscovery of nature might have been antedated by centuries. But this was a change of heart for which the world had long to wait; something much less was the earliest biological gift of Greece. The gift, when it came, came in two forms, one of which has not been adequately recognized, but both are equally her legacy. These two forms are, firstly, the well-known work of the early translators and, secondly, the tardily recognized work of certain schools of minor art.

The earliest biological treatises to become accessible in the west were rendered not from Greek but from Arabic.[44] The first of them was perhaps the treatise περι μυων κινησεως {peri myôn kinêseôs}, _On movement of muscles_ of Galen, a work which contains more than its title suggests and indeed sets forth much of the Galenic physiological system. It was rendered into Latin from the Arabic of Joannitius (Hunain ibn Ishaq, 809-73), probably about the year 1200, by one Mark of Toledo. It attracted little attention, but very soon after biological works of Aristotle began to become accessible. The first was probably the fragment _On plants_. The Greek original of this is lost, and besides the Latin, only an Arabic version of a former Arabic translation of a Syriac rendering of a Greek commentary is now known! Such a work appeared from the hand of a translator known as Alfred the Englishman about 1220 or a little later. Neither it nor another work from the same translator, _On the motion of the heart_, which sought to establish the primacy of that organ on Aristotelian grounds, can be said to contain any of the spirit of the master.[45]

[44] The early European translations from the Arabic are tabulated with unparalleled learning by M. Steinschneider, 'Die Europäischen Uebersetzungen aus dem Arabischen bis Mitte des 17. Jahrhunderts', in the _Sitzungsberichte der kais. Akad. der Wissenschaften in Wien_, cxlix and cli, Vienna, 1904 and 1905.

[45] C. H. Haskins, 'The reception of Arabic science in England,' _English Historical Review_, London, 1915, p. 56.

A little better than these is the work of the wizard Michael the Scot (1175?-1234?). Roger Bacon tells us that Michael in 1230 'appeared [at Oxford], bringing with him the works of Aristotle in natural history and mathematics, with wise expositors, so that the philosophy of Aristotle was magnified among the Latins'.[46] Scott produced his work _De animalibus_ about this date and he included in it the three great biological works of Aristotle, all rendered from an inferior Arabic version.[47] Albertus Magnus (1206-80) had not as yet a translation direct from the Greek to go upon for his great commentary on the _History of animals_, but he depended on Scott. The biological works of Aristotle were rendered into Latin direct from the Greek in the year 1260 probably by William of Moerbeke.[48] Such translations, appearing in the full scholastic age when everything was against direct observation, cannot be said to have fallen on a fertile ground. They presented an ordered account of nature and a good method of investigation, but those were gifts to a society that knew little of their real value.[49]

[46] Roger Bacon, _Opus majus_, edited by J. H. Bridges, 3 vols., London, 1897-1900. Vol. iii, p. 66.

[47] On the Aristotelian translations of Scott see A. H. Querfeld, _Michael Scottus und seine Schrift, De secretis naturae_, Leipzig, 1919; and C. H. Haskins, 'Michael Scot and Frederick II' in _Isis_, ii. 250, Brussels, 1922.

[48] J. G. Schneider, _Aristotelis de animalibus historiae_, Leipzig, 1811, p. cxxvi. L. Dittmeyer, _Guilelmi Moerbekensis translatio commentationis Aristotelicae de generatione animalium_, Dillingen, 1915. L. Dittmeyer, _De animalibus historia_, Leipzig, 1907.

[49] The subject of the Latin translations of Aristotle is traversed by A. and C. Jourdain, _Recherches critiques sur l'âge des traductions latines d'Aristote_, 2nd ed., Paris, 1843; M. Grabmann, _Forschungen uber die lateinischen Aristoteles Ubersetzungen des XIII. Jahrhunderts_, Münster i/W., 1916; and F. Wüstenfeld, _Die Ubersetzungen arabischer Werke in das Lateinische seit dem XI. Jahrhundert_, Göttingen, 1877.

Yet the advent of these texts was coincident with a returning desire to observe nature. Albert, with all his scholasticism, was no contemptible naturalist. He may be said to have begun first-hand plant study in modern times so far as literary records are concerned. His book _De vegetabilibus_ contains excellent observations, and he is worthy of inclusion among the fathers of botany. In his vast treatise _De animalibus_, hampered as he is by his learning and verbosity, he shows himself a true observer and one who has absorbed something of the spirit of the great naturalist to whose works he had devoted a lifetime of study and on which he professes to be commenting. We see clearly the leaven of the Aristotelian spirit working, though Albert is still a schoolman. We may select for quotation a passage on the generation of fish, a subject on which some of Aristotle's most remarkable descriptions remained unconfirmed till modern times. These descriptions impressed Albert in the same way as they do the modern naturalist. To those who know nothing of the stimulating power of the Aristotelian biological works, Albert's description of the embryos of fish and his accurate distinction of their mode of development from that of birds, by the absence of an allantoic membrane in the one and its presence in the other, must surely be startling. Albert depends on Aristotle--a third-hand version of Aristotle--but does not slavishly follow him.

'Between the mode of development (_anathomiam generationis_) of birds' and fishes' eggs there is this difference: during the development of the fish the second of the two veins which extend from the heart [as described by Aristotle in birds] does not exist. For we do not find the vein which extends to the outer covering in the eggs of birds which some wrongly call the navel because it carries the blood to the exterior parts; but we do find the vein that corresponds to the yolk vein of birds, for this vein imbibes the nourishment by which the limbs increase.... In fishes as in birds, channels extend from the heart first to the head and the eyes, and first in them appear the great upper parts. As the growth of the young fish increases the albumen decreases, being incorporated into the members of the young fish, and it disappears entirely when development and formation are complete. The beating of the heart ... is conveyed to the lower part of the belly, carrying pulse and life to the inferior members.

'While the young [fish] are small and not yet fully developed they have veins of great length which take the place of the navel-string, but as they grow and develop, these shorten and contract into the body towards the heart, as we have said about birds. The young fish and the eggs are enclosed and in a covering, as are the eggs and young of birds. This covering resembles the dura mater [of the brain], and beneath it is another [corresponding therefore to the pia mater of the brain] which contains the young animal and nothing else.'[50]

[50] The enormous _De Animalibus_ of Albert of Cologne is now available in an edition by H. Stadler, _Albertus Magnus De Animalibus Libri XXVI nach der cölner Urschrift_, 2 vols., Münster i/W., 1916-21. The quotation is translated from vol. i, pp. 465-6.

In the next century Conrad von Megenberg (1309-98) produced his _Book of Nature_, a complete work on natural history, the first of the kind in the vernacular, founded on Latin versions, now rendered direct from the Greek, of the Aristotelian and Galenic biological works. It is well ordered and opens with a systematic account of the structure and physiology of man as a type of the animal creation, which is then systematically described and followed by an account of plants. Conrad, though guided by Aristotle, uses his own eyes and ears, and with him and Albert the era of direct observation has begun.[51]

[51] Conrad's work is conveniently edited by H. Schultz, _Das Buch der Natur von Conrad von Megenberg, die erste Naturgeschichte in deutscher Sprache, in Neu-Hochdeutsche Sprache bearbeitet_, Greifswald, 1897. Conrad's work is based on that of Thomas of Cantimpré (1201-70).

But there was another department in which the legacy of Greece found an even earlier appreciation. For centuries the illustrations to herbals and bestiaries had been copied from hand to hand, continuing a tradition that had its rise with Greek artists of the first century B. C. But their work, copied at each stage without reference to the object, moved constantly farther from resemblance to the original. At last the illustrations became little but formal patterns, a state in which they remained in some late copies prepared as recently as the sixteenth century. But at a certain period a change set in, and the artist, no longer content to rely on tradition, appeals at last to nature. This new stirring in art corresponds with the new stirring in letters, the Arabian revival--itself a legacy of Greece, though sadly deteriorated in transit--that gave rise to scholasticism. In much of the beautiful carved and sculptured work of the French cathedrals the new movement appears in the earlier part of the thirteenth century. At such a place as Chartres we see the attempt to render plants and animals faithfully in stone as early as 1240 or before. In the easier medium of parchment the same tendency appears even earlier. When once it begins the process progresses slowly until the great recovery of the Greek texts in the fifteenth century, when it is again accelerated.

During the sixteenth century the energy of botanists and zoologists was largely absorbed in producing most carefully annotated and illustrated editions of Dioscorides and Theophrastus and accounts of animals, habits, and structure that were intended to illustrate the writings of Aristotle, while the anatomists explored the bodies of man and beast to confirm or refute Galen. The great monographs on birds, fishes, and plants of this period, ostensibly little but commentaries on Pliny, Aristotle, and Dioscorides, represent really the first important efforts of modern times at a natural history. They pass naturally into the encyclopaedias of the later sixteenth century, and these into the physiological works of the seventeenth. Aristotle was never a dead hand in Biology as he was in Physics, and this for the reason that he was a great biologist but was not a great physicist.

With the advance of the sixteenth century the works of Aristotle, and to a less extent those of Dioscorides and Galen, became the great stimulus to the foundation of a new biological science. Matthioli (1520-77), in his commentary on Dioscorides (first edition 1544), which was one of the first works of its type to appear in the vernacular, made a number of first-hand observations on the habits and structure of plants that is startling even to a modern botanist. About the same time Galenic physiology, expressed also in numerous works in the vulgar tongue and rousing the curiosity of the physicians, became the clear parent of modern physiology and comparative anatomy. But, above all, the Aristotelian biological works were fertilizers of the mind. It is very interesting to watch a fine observer such as Fabricius ab Acquapendente (1537-1619) laying the foundations of modern embryology in a splendid series of first-hand observations, treating his own great researches almost as a commentary on Aristotle. What an impressive contrast to the arid physics of the time based also on Aristotle! 'My purpose', says Fabricius, 'is to treat of the formation of the foetus in every animal, setting out from that which proceeds from the egg: for this ought to take precedence of all other discussion of the subject, both because it is not difficult to make out Aristotle's view of the matter, and because his treatise on the Formation of the Foetus from the egg is by far the fullest, and the subject is by much the most extensive and difficult.'[52]

[52] Hieronimo Fabrizio of Acquapendente, _De formato foetu_, Padua, 1604.

The industrious and careful Fabricius, with a wonderful talent for observation lit not by his own lamp but by that of Aristotle, bears a relation to the master much like that held by Aristotle's pupil in the flesh, Theophrastus. The works of the two men, Fabricius and Theophrastus, bear indeed a resemblance to each other. Both rely on the same group of general ideas, both progress in much the same ordered calm from observation to observation, both have an inspiration which is efficient and stimulating but below the greatest, both are enthusiastic and effective as investigators of fact, but timid and ineffective in drawing conclusions.

But Fabricius was more happy in his pupils than Theophrastus, for we may watch the same Aristotelian ideas fermenting in the mind of Fabricius's successor, the greatest biologist since Aristotle himself, William Harvey (1578-1657).[53] This writer's work _On generation_ is a careful commentary on Aristotle's work on the same topic, but it is a commentary not in the old sense but in the spirit of Aristotle himself. Each statement is weighed and tested in the light of experience, and the younger naturalist, with all his reverence for Aristotle, does not hesitate to criticize his conclusions. He exhibits an independence of thought, an ingenuity in experiment, and a power of deduction that places his treatise as the middle term of the three great works on embryology of which the other members are those of Aristotle and Karl Ernst von Baer (1796-1876).[54]

[53] William Harvey, _Exercitationes de generatione animalium_, London, 1651.

[54] Karl Ernst von Baer, _Ueber die Entwickelungsgeschichte der Thiere_, Königsberg, 1828-37.

With the second half of the seventeenth century and during a large part of the eighteenth the biological works of Aristotle attracted less attention. The battle against the Aristotelian physics had been fought and won, but with them the biological works of Aristotle unjustly passed into the shadow that overhung all the idols of the Middle Ages.

The rediscovery of the Aristotelian biology is a modern thing. The collection of the vast wealth of living forms absorbed the energies of the generations of naturalists from Ray (1627-1705) and Willoughby (1635-72) to Réaumur (1683-1757) and Linnaeus (1707-1778) and beyond to the nineteenth century. The magnitude and fascination of the work seems almost to have excluded general ideas. With the end of this period and the advent of a more philosophical type of naturalist, such as Cuvier (1769-1832) and members of the Saint-Hilaire family, Aristotle came again to his own. Since the dawn of the nineteenth century, and since naturalists have been in a position to verify the work of Aristotle, his reputation as a naturalist has continuously risen. Johannes Müller (1801-58), Richard Owen (1804-92), George Henry Lewes (1817-78), William Ogle (1827-1912) are a few of the long line of those who have derived direct inspiration from his biological work. With improved modern methods of investigation the problems of generation have absorbed a large amount of biological attention, and interest has become specially concentrated on Aristotle's work on that topic which is perhaps, at the moment, more widely read than any biological treatise, ancient or modern, except the works of Darwin. That great naturalist wrote to Ogle in 1882: 'From quotations I had seen I had a high notion of Aristotle's merits, but I had not the most remote notion what a wonderful man he was. Linnaeus and Cuvier have been my two gods, though in very different ways, but they were mere schoolboys to old Aristotle.'

CHARLES SINGER.

MEDICINE

Ἡροφιλος δε εν τω Διαιτητικω και σοφιαν φησιν ανεπιδεικτον και τεχνην αδηλον και ισχυν αναγωνιστον και πλουτον αχρειον και λογον αδυνατον, ὑγιειας απουσης.

{Hêrophilos de en tô Diaitêtikô kai sophian phêsin anepideikton kai technên adêlon kai ischyn anagôniston kai plouton achreion kai logon adynaton, hygieias apousês.}

Herophilos, a Greek philosopher and physician (_c._ 300 B. C.), has truly written 'that Science and Art have equally nothing to show, that Strength is incapable of effort, Wealth useless, and Eloquence powerless if Health be wanting'.[55] All peoples therefore have had their methods of treating those departures from health that we call disease, and among peoples of higher culture such methods have been reduced in most cases to something resembling a system. In antiquity, as now, a variety of such systems were in vogue, and those nations who practised the art of writing from an early date have left considerable records of their medical methods and doctrines. We may thus form a fairly good idea of the medical principles of the Mesopotamian, the Egyptian, the Iranian, the Indian, and the Chinese civilizations. Much in these systems, as in the medical procedure of more primitive tribes, was based upon some theory of disease which fitted in with a larger theory of the nature of evil. Of these theories the commonest was and is the demonic, the view that regards deviation from the normal state of health as due either to the attacks of supernatural beings or to their actual entry into the body of the sufferer. A medical system based on such a view is susceptible of great elaboration in a higher civilization, but not being founded on observation is hardly capable of indefinite development, for a point must ultimately be reached at which the mind recoils from complex conclusions far remote from observed phenomena. The medicine of the ancient and settled civilization of such a people as the Assyro-Babylonians, for instance, of which substantial traces have been recovered, is hardly, if at all, more effective, though far more systematized, than that of many a wild and unlettered tribe that may be observed to-day. Of such medicine as this we may give an account, but we can hardly write a _history_. We cannot establish those elements of continuity and of development from which alone history can be constructed.

[55] The works of Herophilus are lost. This fine passage has been preserved for us by Sextus Empiricus, a third-century physician, in his προς τοις μαθηματικους αιτιρρητικοι {pros tois mathêmatikous aitirrêtikoi}, which is in essence an attack on all positive philosophy. It is an entertaining fact that we should have to go to such a work for remains of the greatest anatomist of antiquity. The passage is in the section directed against ethical writers, xi. 50.

It is the distinction of the Greeks alone among the nations of antiquity that they practised a system of medicine based not on theory but on observation accumulated systematically as time went on. The claim can be made for the Greeks that some at least among them were deflected by no theory, were deceived by no theurgy, were hampered by no tradition in their search for the facts of disease and in their attempts at interpreting its phenomena. Only the Greeks among the ancients could look on their healers as _physicians_ (= naturalists, φυσις {physis} = nature), and that word itself stands as a lasting reminder of their achievement.[56]

[56] The word φυσικος {physikos}, though it passed over into Latin (Cicero) with the meaning _naturalist_, acquired the connotation of _sorcerer_ among the later Greek writers. Perhaps the word _physicianus_ was introduced to make a distinction from the charm-mongering _physicus_. In later Latin _physicus_ and _medicus_ are almost always interchangeable.

At a certain stage in the history of the Western world--the exact point in time may be disputed but the event is admitted by all--men turned to explore the treasures of the ancient wisdom and the whole mass of Greek medical learning was gradually laid before the student. That mass contained much dross, material that survived from early as from late Greek times which was hardly, if at all, superior to the debased compositions that circulated in the name of medicine in the middle centuries. But the recovered Greek medical writings also contained some material of the purest and most scientific type, and that material and the spirit in which it was written, form the debt of modern medicine to antiquity.

It is a debt the value of which cannot be exaggerated. The physicians of the revival of learning, and for long after, doubtless pinned their faith too much to the written word of their Greek forbears and sought to imprison the free spirit of Hippocrates and Galen in the rigid wall of their own rediscovered texts. The great medical pioneers of a somewhat later age, enraged by this attempt, the real nature of which was largely hidden from them, not infrequently revolted and rightly revolted against the bondage to the Greeks in which they had been brought up. Yet it is sure that these modern discoverers were the true inheritors of the Greeks. Without Herophilus we should have had no Harvey and the rise of physiology might have been delayed for centuries; had Galen's works not survived, Vesalius would never have reconstructed Anatomy, and Surgery too might have stayed behind with her laggard sister, Medicine; the Hippocratic collection was the necessary and acknowledged basis for the work of the greatest of modern clinical observers, Thomas Sydenham, and the teaching of Hippocrates and of his school is the substantial basis of instruction in the wards of a modern hospital. In the pages which follow we propose therefore to review the general character of medical knowledge in the best Greek period and to consider briefly how much of that great heritage remained accessible to the earlier modern physicians. The reader will thus be able to form some estimate of the degree to which the legacy has been passed on to our own times.

It is evident that among such a group of peoples as the Greeks, varying in state of civilization, in mental power, in geographical and economic position and in general outlook, the practice of medicine can have been by no means uniform. Without any method of centralizing medical education and standardizing teaching there was a great variety of doctrines and of practice in vogue among them, and much of this was on a low level of folk custom. Such lower grade material of Greek origin has come down to us in abundance, though much of it, curiously enough, from a later time. But the overwhelming mass of earlier Greek medical literature sets forth for us a pure scientific effort to observe and to classify disease, to make generalizations from carefully collected data, to explain the origin of disease on rational grounds, and to apply remedies, when possible, on a reasoned basis. We may thus rest fairly well assured that, despite serious and irreparable losses, we are still in possession of some of the very finest products of the Greek medical intellect.

There is ample evidence that the Greeks inherited, in common with many other peoples of Mediterranean and Asiatic origin, a whole system of magical or at least non-rational pharmacy and medicine from a remoter ancestry. Striking parallels can be drawn between these folk elements among the Greeks and the medical systems of the early Romans, as well as with the medicine of the Indian Vedas, of the ancient Egyptians, and of the earliest European barbarian writings. It is thus reasonable to suppose that these elements, when they appear in later Greek writings, represent more primitive folk elements working up, under the influence of social disintegration and consequent mental deterioration, through the upper strata of the literate Greek world. But with these elements, intensely interesting to the anthropologist, the psychologist, the ethnologist, and to the historian of religion, we are not here greatly concerned. Important as they are, they constitute no part of the special claim of the Greek people to distinction, but rather aid us in uniting the Greek mentality with that of other kindred peoples. Here we shall rather discuss the course of Greek scientific medicine proper, the type of medical doctrine and practice, capable of development in the proper sense of the word, that forms the basis of our modern system. We are concerned, in fact, with the earliest evolutionary medicine.

We need hardly discuss the first origins of Greek Medicine. The material is scanty and the conclusions somewhat doubtful and perhaps premature, for the discovery of a considerable fragment of the historical work of Menon, a pupil of Aristotle, containing a description of the views of some of the precursors of the Hippocratic school, renews a hope that more extended investigation may yield further information as to the sources and nature of the earliest Greek medical writings.[57] The study of Mesopotamian star-lore has linked it up with early Greek astronomical science. The efforts of cuneiform scholars have not, however, been equally successful for medicine, and on the whole the general tendency of modern research is to give less weight to Mesopotamian and more to Egyptian sources than had previously been admitted; thus very recently an Egyptian medical papyrus of about 1700 B. C. has been described which bears a distinct resemblance to some of the Hippocratic treatises.[58] A number of drugs, too, habitually used by the Greeks, such as _Andropogon_, _Cardamoms_, and _Sesame orientalis_, are of Indian origin. There are also the Minoan cultures to be considered, and though our knowledge is not yet sufficient to speak of the heritage that Greek medicine may or may not have derived from that source, it seems not improbable that Greek hygiene may here owe a debt.[59] Omitting, therefore, this early epoch, we pass direct to the later period, between the sixth and fourth centuries, from which documents have actually come down to us.

[57] This fragment has been published in vol. iii,