Spiders. 393 



DIVING WATER- SPIDER. 



Though spiders require atmospheric air for respiration, 

 yet one species well known to naturalists is aquatic in its 

 habits, and lives not only upon the surface but below the 

 surface of the water, contriving to carry down with it a 

 sufficiency of air for the support of life during a considerable 

 period of time. Its subaqueous nest is in fact a sort of 

 diving-bell, and constitutes a secure and most ingenious habi- 

 tation. This spider does not like stagnant water, but prefers 

 low running streams, canals, and ditches, where she may 

 often be seen in the vicinity of London and elsewhere, living 

 in her diving-bell, which shines through the water like 

 a little globe of silver : her singular economy was first, 

 we believe, described by Clerck,* L. M. de Lignac,f and De 

 Geer. 



" The shining appearance," says Clerck, " proceeds either 

 from an inflated globule surrounding the abdomen, or from 

 the space between the body and the water. The spider, 

 when wishing to inhale the air, rises to the surface, with its 

 body still submersed, and only the part containing the 

 spinneret rising just to the surface, when it briskly opens 

 and moves its four teats. A thick coat of hair keeps the 

 water from approaching or wetting the abdomen. It comes 

 up for air about four times an hour or oftener, though I have 

 good reason to suppose it can continue without it for several 

 days together. 



" I found in the middle of May one male and ten females, 

 which I put into a glass filled with water, where they lived 

 together very quietly for eight days. I put some duckweed 

 (Lemna) into the glass to afford them shelter, and the females 

 began to stretch diagonal threads in a confused manner from 

 it to the sides of the glass about half-way down. Each of 

 the females afterwards fixed a close bag to the edge of the 

 glass, from which the water was expelled by the air from the 

 spinneret, and thus a cell was formed capable of containing 



* Aranei Suecici, Stockholm, 1757. 



f Mem. des Anvign. Aquat., 12mo. Paris, 1799. 



