III.

How Long They Can Remain In The Atmosphere?

At this portion of my history I have to relate facts the most curious and unexpected; and, unfortunately for me, more true than probable. I acknowledge I was loath to publish them, or assume concerning them any responsibility. But I was firmly convinced, and therefore hoped to be believed, especially by this generation of fearless naturalists, who are astonished at nothing in nature, and who, having often been surprised in the relation of almost incredible marvels, must certainly make allowances for a few more in another quarter.

Let us look at, for instance, the wonderful things related of the _argyronete_, or aquatic spider. [Footnote 97]

[Footnote 97: The _argyronete_ is a spider that lives in the water where she constructs a charming little edifice that appears surrounded with a silky mortar. The down that covers her contains a certain quantity of air for respiration. This gives her in swimming the appearance of a ball of quicksilver, from which we have her name.]

I could not tell anything more unlikely, so I will only exact for the atmosphere a companion to what the Père de Lignac discovered in the last century for the water. Yes, I pretend there are spiders that live in the air as well as those living in water, and that every year, from the earliest days of spring, there is, unknown to us, a general migration of spiders toward the atmosphere, where they pass their best season, form their nets, chase their prey, and only return to earth in the first fogs of autumn to find their quarters for the winter. I add, also, that this ascent and descent give rise to the curious phenomenon, still so badly explained, of the gossamer. And as it was to the study of this phenomenon that I owe my knowledge of the rest, may I be permitted here, by way of demonstration, to relate briefly the path I have followed and the proofs which have led to the conviction I express?

Attracted, as I was, by all that concerns spiders, I could not remain indifferent to a fact so important and interesting as the periodical apparition of those threads which in spring and autumn we see flying about in long white skeins, clinging to trees, to hedges, and to the vestments of the passers-by, carpeting the country in a few hours with more silk, and finer and whiter, than could be spun in a year by all the reels in the world. Admirable netting, glistening in the light of the setting sun, and reflecting the sweetest, softest tints of gold, vermilion, and emerald, and receiving the pretty and poetical name of "_fils de la Vierge_." Was there not between this phenomenon and my preceding observations a secret tie, some mysterious relation? I seemed to foresee it, and, setting to work immediately, rejected from the very beginning the usual explanation of this phenomenon.

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How, indeed, can we admit these floating gossamers as merely the refuge webs of spiders, torn by the violence of the wind from the trees and forests and carried capriciously through the air? Will not the slightest observation convince us that they never appear but in the calmest moments, on days foggy in the morning, but afterward beautiful, and not preceding a storm; never in summer, often in the spring and autumn, and sometimes even in winter? If the winds carry them, why do they not appear in summer? Are violent winds and spider-webs both wanting? And who has ever seen one of these webs carried by a hurricane, especially in quantity sufficient to produce such a phenomenon? For the fall of gossamers sometimes lasts for almost entire days, and in certain countries during the middle of the day the fields are covered with them. Add, too, that violent winds are generally local, while this phenomenon is universal, and so periodical that in the same climates it appears at the same epochs, and, when one knows what produces it, it is easy to predict the time and day of the apparition.

Discontented, then, on this point with books and their explanations, I turn completely to the side of nature, and present all I observed.

From the first appearance of these threads in autumn, I was struck with the immense multitudes of new spiders met with everywhere, and which I had not seen during the summer. Little brown _lycoses_ filled the air, so that it seemed as if it had rained them. If one walked in the fields, the meadows, the gardens, on the borders of the woods, among heaps of dried leaves, scattered all through the forest everywhere, could be seen myriads of these little brown spiders, jumping up and flying before me in every direction, and exactly such as I had already recognized as such excellent swimmers. After having passed the winter in the earth, in the holes of worms that they completed with a little silk, they reappeared after the cold in great numbers, to disappear again entirely in the first bright days of spring, and as if by enchantment. If one is seen again during the summer, we may be sure it is some female retarded by laying her eggs, and dragging laboriously her cocoon after her. Now, what has become of the others?

For several months I could not satisfy myself on this point, when, on the 21 St of October, 1856, in the enclosure of the little seminary of Iseure, near Moulins, I came to a positive decision, I was observing the fall of a large quantity of gossamers, which were falling on that day in large white flakes, when I perceived close to me in the air one of those little black spiders descending gradually, and as if she were jumping. She held by an invisible thread to a large flake, which came down slowly about seven or eight yards above her; but, keeping outside of it, she hung by the end of the long thread, like an aeronaut underneath his balloon. My attention once attracted, I noticed so great a number that I was astonished I had not taken care sooner; for there was scarcely a flake underneath which there were not one or two, and this sometimes even before the flake itself was visible. [Footnote 98]

[Footnote 98: There is an observation which confirms my own. We read in _Darwin's Journal_, page 159: "Mr. Darwin saw a large number of gossamers on the ship Beagle, when she was about 60 miles from the mouth of the Rio de la Plata. It was the first of November, and these gossamers were carried by a very light breeze, and on each were found an immense number of little spiders, similar in appearance, about the twelfth of an inch in length, and in color a deep brown. The smallest were a deeper shade than the others. None were found on the white tufts, but all on threads." _Journal of Researches into the Natural History and Geology of the Countries visited during the Voyage of his Majesty's Ship, the Beagle,_ 1845.]

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Each one was separated by a slender thread, and followed the motion of its balloon. If they met a tree or a bush, they landed upon it; if not, coming close to the earth, they ran along and were lost in the verdure. If I approached them too quickly or made a noise, they remounted rapidly by their threads and went to disembark somewhere else.

I also examined some of the flakes. They were all shining white mats, appearing as if they had been washed. Several contained wings and feet of flies, fragments of the case of little coleoptera, and other remnants of their aerial festivities.

This encounter was for me a revelation. I knew where the spiders, whom I had seen disappear so brusquely, took refuge, and, however rash my judgment may appear, I felt assured I had solved an interesting problem.

But to establish seriously and give to science an opinion so new and original as that the atmosphere may be peopled with spiders, I soon felt that more proof was necessary in order to sit down calmly under my personal conviction. So I concluded I should not be doing too much if I added to the verification of their descent that of their ascension, and could surprise them in this new migration. I waited, therefore, impatiently for the spring.

But that spring, and for five or six that followed it, great was my disappointment; for, though I perceived several isolated ascensions, yet nothing in the proportion I had imagined or that could justify my hypothesis. I began then to doubt seriously my success, when an incident occurred that relieved my embarrassment, and proved how trifling sometimes are the causes which lift the veil from nature. I was looking straight upward, but sitting close to the earth, and so as to be able as much as possible to exclude the sun from my eyes. And here, by the way, a fact is made palpable, by no means microscopic, but which has escaped so long not merely the observation of the crowd of vulgar observers, but of those even who are wide awake and study carefully; namely, that it is not necessary to carry one's nose always in the air, if I may so express myself, to examine closely, to investigate, or to render a faithful account of phenomena.

On looking upward--as an ascension only takes place on very beautiful days, succeeding generally to bad weather--spiders cannot be distinguished from the multitude of other insects which fill the air. But if, on a beautiful day, mild, calm, and brilliant in sunlight, succeeding as nearly as possible to a rain warm with the south wind, at about nine or ten o'clock in the morning, a post is chosen on an eminence of a meadow or an avenue, and there, as near the ground as may be, and crouching low, the observer will look horizontally, he will perceive a series of fire-works, formed of innumerable threads launched from every direction and inclined toward the sky. This is the prelude. Soon the spiders detach themselves and mount slowly by their threads. The most conspicuous are the _thomises bufo_, because they are the largest, and because they only ascend with an entire bundle of threads, which gives them the appearance of small comets.

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Thus have I decided

1st. That there is not only one ascension every year, but several, at least partial ones; that they do not always take place in spring, but often in the autumn, and sometimes even in the winter; and in general, from the descent which has taken place in the beginning of autumn until the definitive ascension in the spring, there are but few favorable days of which the spiders do not profit to make an aerial journey, or at least to throw out a large number of threads. Thus, in the Beaujolais, where I have lived for several years, there were partial ascensions on the 1st, the 19th, and the 28th of November, 1864; the 21st, the 23d, and especially the 25th of October, the 9th of November, and the 6th of December, 1865. In 1866, the 18th and the 30th of January, the 3d of February, the 3d, 14th, and 31st of October, and the 17th of December. In 1867, the 10th of February, ... the last, however, less considerable than might have been predicted by the beauty of the day. The day previous was so mild, though cloudy, that many of the spiders may have embarked _incognito_. Many, also, may not have judged it _a propos_ to fly away, for a great number still remained on the ground. I forgot to observe the temperature of all the days I have noted. The director of the Normal School of Villefranche having had the kindness to show me the meteorological register which he had kept with great care, I was able to prove that in calm weather only ten or twelve degrees of heat were necessary to induce them to mount upward. The least exposed begin; then immediately the others, so soon as the heat reaches them; but after three or four o'clock in the afternoon no more ascensions are perceived, unless they are provoked; and this does not always succeed,

2d. Before taking their flight, they generally cling to some elevated object that they meet with easily, such as shrubs, bushes, props of vines, or blades of grass escaped from the scythe. To these they affix their threads and warm themselves well in the sun before commencing their excursion. This is the happy moment for amateurs to make their observations, for there is scarcely a blade of grass that does not contain one or more; and, if the branches of young trees are suddenly struck with a slight blow, a great number are detached, suspended at the end of their threads; and very often rare specimens are thus found not discoverable elsewhere.