THE WATER SPIDER. 505 



The last example upon this illustration (Fig. Gr) is a really remarkable creature, whose 

 habits have been studied by M. Dufour. That careful naturalist found it in the Pyrenees, 

 in Catalonia, and in the mountains of Narbonne. It has also been discovered in Egypt and 

 Dalmatia. 



Of this Arachnidan, M. Dufour gives a most interesting description, from which the follow- 

 ing passage is extracted : — 



"It makes at the inferior surface of large stones, and in the clefts of rocks, a cocoon, in 

 the form of a cap, or little dish, a good inch in diameter. Its contour presents seven or eight 

 emarginations, of which the angles alone are fixed upon the stone, by means of bundles of 

 thread, while the edges are free. This singular tent is of an admirable texture ; the exterior 

 resembles the finest taffetas, composed, according to the age of the worker, of a greater or less 

 number of doublings. 



"Thus, when the Uroctea (another name for the Clotho), as yet young, commences to estab- 

 lish its retreat, it only fabricates two webs, between which it remains in shelter. Subsequently, 

 and, I believe, at each moulting, it adds a certain number of doubles. Finally, when the 

 period marked for reproduction arrives, it weaves a cell for this very purpose, more downy 

 and soft, where the sacs of eggs, and the young ones newly disclosed, are to be shut up. 

 Although the external cap or pavilion is designedly, without doubt, more or less soiled by 

 foreign bodies, which serve to conceal its presence, the apartments of the industrious fabrica- 

 tion are always scrupulously clean." 



The curious and interesting Water Spider is now far better known than was formerly 

 the case, as the aquaria that have been established have tended to familiarize many people 

 with this as well as with many other inhabitants of the water. 



This creature leads a strange life. Though a really terrestrial being, and needing to 

 respire atmospheric air, it passes nearly the whole of its life in the water, and. for the greater 

 part of its time, is submerged below the surface. To a lesser degree, several other spiders lead a 

 somewhat similar life, sustaining existence by means of the air which is entangled in the hairs 

 which clothe the body. Their submerged existence is, however, only accidental, while in the 

 Water Spider it forms the constant habit of its life. 



Like the pirate-spider, this creature is purposely covered with hairs, which serve to 

 entangle a large comparative amount of atmospheric air, but it has other means which are 

 not possessed by the species already described. It has the power of diving below the surface, 

 and carrying with it a very large bubble of air, that is held in its place by the hind-legs; 

 and in spite of this obstacle to its progress, it can pass through the water with tolerable 

 speed. 



The strangest part in the economy of this creature is, that it is actually hatched under 

 water, and lies submerged for a considerable time before it ever sees the land. At some little 

 depth the mother spider spins a kind of egg or dome-shaped cell, with the opening down- 

 wards. Having made this chamber, she ascends to the surface, and there charges her whole 

 body with air, arranging her hind-legs in such a manner that the great bubble cannot escape. 

 She then dives into the water, proceeds to her nest, and discharges the bubble into it. A 

 quantity of water is thus displaced, and the upper part of the cell is tilled with air. She then 

 returns for a second supply, and so proceeds until the nest is full of air. 



In this curious domicile the spider lives, and is thus able to deposit and to hatch her eggs 

 under the water without even wetting them. Tire reader will have noticed the exact analogy 

 between this sub-aquatic residence and the diving-bell, now so generally employed. As to the 

 spider itself, it is never wet ; and though it may be seen swimming rapidly about in the water. 

 yet the moment it emerges from the surface, its hairy body will be found as dry as that of any 

 land spider. The reason for this phenomenon is, that the minute bubbles of air which always 

 cling to the furred body repel the water and prevent it from moistening the skin. 



The eggs of this spider are inclosed in a kind of cap-shaped cocoon, not unlike the cover 

 of a circular vegetable dish. This cocoon usually contains about a hundred little spherical 

 eggs, which are not glued together. 



Vol. Ill — W 



