Chapter VI

. Lamarck discusses direct or spontaneous generation in the same way as in 1802. In the following paragraph we have foreshadowed the characteristic qualities of the primeval protoplasmic matter fitted to receive the first traces of organization and life:

"Every mass of substance homogeneous in appearance, of a gelatinous or mucilaginous consistence, whose parts, coherent among themselves, will be in the state nearest fluidity, but will have only a consistence sufficient to constitute containing parts, will be the body most fitted to receive the first traces of organization and life."

In the third part of the _Philosophie zoologique_ Lamarck considers the physical causes of feeling--_i.e._, those which form the productive force of actions, and those giving rise to intelligent acts. After describing the nervous system and its functions, he discusses the nervous fluid. His physiological views are based on those of Richerand's _Physiologie_, which he at times quotes.

Lamarck's thoughts on the nature of the nervous fluid (_Recherches sur le fluide nerveux_) are curious and illustrative of the gropings after the truth of his age.

He claims that the supposed nervous fluid has much analogy to the electric, that it is the _feu éthéré_ "animalized by the circumstances under which it occurs." In his _Recherches sur l'organisation des corps vivans_ (1802) he states that, as the result of changes continually undergone by the principal fluids of an animal, there is continually set free in a state of _feu fixé_ a special fluid, which at the instant of its disengagement occurs in the expansive state of the caloric, then becomes gradually rarefied, and insensibly arrives at the state of an extremely subtile fluid which then passes along the smallest nervous ramifications in the substance of the nerve, which is a very good conductor for it. On its side the brain sends back the subtile fluid in question along the nerves to the different organs.

In the same work (1802) Lamarck defines thought as a physical act taking place in the brain. "This act of thinking gives rise to different displacements of the subtile nervous fluid and to different accumulations of this fluid in the parts of the brain where the ideas have been traced." There result from the flow of the fluid on the conserved impressions of ideas, special movements which portions of this fluid acquire with each impression, which give rise to compounds by their union producing new impressions on the delicate organ which receives them, and which constitute abstract ideas of all kinds, also the different acts of thought.

All the acts which constitute thought are the comparisons of ideas, both simple and complex, and the results of these comparisons are judgments.

He then discusses the influence of the nervous fluid on the muscles, and also its influence considered as the cause of feeling (_sentiment_). Finally he concludes that _feu fixé_, caloric, the nervous fluid, and the electric fluid "are only one and the same substance occurring in different states."

FOOTNOTES:

[107] Charles Bonnet (1720-1793), a Swiss naturalist, is famous for his work on Aphides and their parthenogenetic generation, on the mode of reproduction in the Polyzoa, and on the respiration of insects. After the age of thirty-four, when his eyesight became impaired, he began his premature speculations, which did not add to his reputation. Judging, however, by an extract from his writings by D'Archiac (_Introduction à l'Étude de la Paléontologie stratigraphique_, ii., p. 49), he had sound ideas on the theory of descent, claiming that "la diversité et la multitude des conjunctions, peut-être même la diversité des climats et des nourritures, ont donné naissance à de nouvelles espèces ou à des individus intermédiaires" (_Oeuvres d'Hist. nat. et de Philosophie_, in-8vo, p. 230, 1779).

[108] See his remark: "_On a dit avec raison que tout ce qui a vie provient d'un auf_" (_Mémoires de Physique_, etc., 1797, p. 272). He appears, however, to have made the simplest organisms exceptions to this doctrine.

[109] _Elementa physiologiae corporis humani_, iv. Lausanne, 1762.

[110] _Theoria generationis_, 1774.

[111] _Mémoires de Physique_, (1797), p. 250.

[112] _Mémoires de Physique_, etc. (1797), p. 272.

[113] Huxley's "Evolution in Biology" (_Darwiniana_, p. 192), where be quotes from Bonnet's statements, which "bear no small resemblance to what is understood by evolution at the present day."

[114] Buffon did not accept Bonnet's theory of preëxistent germs, but he assumed the existence of "_germes accumulés_" which reproduced parts or organs, and for the production of organisms he imagined "_molécules organiques_." Réaumur had previously (1712) conjectured that there were "_germes cachés et accumulés_" to account for the regeneration of the limbs of the crayfish. The ideas of Bonnet on germs are stated in his _Mémoires sur les Salamandres_ (1777-78-80) and in his _Considérations sur les corps organisés_ (1762.)

[115] _Mémoires de Physique_, etc., pp. 318, 319, 324-359. Yet the idea of a sort of continuity between the inorganic and the organic world is expressed by Verworn.

[116] _General Physiology_ (English trans., 1899, p. 17). In France vitalism was founded by Bordeu (1722-1766), developed further by Barthez (1734-1806) and Chaussier (1746-1828), and formulated most distinctly by Louis Dumas (1765-1813). Later vitalists gave it a thoroughly mystical aspect, distinguishing several varieties, such as the _nisus formativus_ or formative effort, to explain the forms of organisms, accounting for the fact that from the egg of a bird, a bird and no other species always develops (_l. c._, p. 18).

[117] _Recherches sur l'organisation des corps vivans_ (1802), p. 70. The same view was expressed in _Mémoires de physique_ (1797), pp. 254-257, 386.

[118] Here might be quoted for comparison other famous definitions of life:

"Life is the sum of the functions by which death is resisted."--Bichat.

"Life is the result of organization."--(?)

"Life is the principle of individuation."--Coleridge ex. Schelling.

"Life is the twofold internal movement of composition and decomposition, at once general and continuous."--De Blainville, who wisely added that there are "two fundamental and correlative conditions inseparable from the living being--an organism and a medium."

"Life is the continuous adjustment of internal relations to external relations."--Herbert Spencer.

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