272 FEESH-WATER AQUARIA. 



saturated the hairs which cover the abdomen that they (the 

 hairs) can no longer do their duty in connection with the 

 respiratory organs. When a spider is found in this condition, 

 it should be placed upon some blotting-paper and under a 

 tumbler until it is perfectly dry. As a healthy spider goes 

 beneath the surface of the water, the latter part of its body 

 looks as if covered with silver, owing to the air which has 

 become entangled among the abdominal hairs. 



Though these spiders can live upon land, they spend the 

 greater portion of their time under water, where they con- 

 struct most ingenious and curious homes, or nests. It is quite 

 an interesting sight to watch one of these very intelligent 

 creatures make its nest. First of all, it begins by weaving 

 a web between the branches of an aquatic plant, or between 

 a stone and one side of the vessel in which it is confined, or 

 in some similar position. When the web is completed, the 

 Argyroneta ascends to the surface of the water, and protrudes 

 above it the extremity of its abdomen, and, with a jerky 

 movement, obtains a bubble of air, which it holds between 

 the latter part of its body and its crossed hindermost legs. 

 The spider then descends with the bubble of air, and 

 discharges it within the web which it has woven. In this 

 way many other bubbles of air are brought beneath the 

 surface of the water and placed inside the web, which, after 

 a time, owing to the accumulation of air within it, assumes 

 the shape and often the size of a lady's thimble (see Fig. 164, 

 in which, for the sake of clearness, the nest is shown as being 

 above the water). In making these journeys for air, the spider 

 climbs up and down a thread which it has stretched between 

 the nest and the surface of the water. The journeys are 

 long or short, according to the depth at which the Argyroneta 

 constructs its nest; for they are sometimes placed quite 

 close to the surface of the water, occasionally very near to 

 its bottom, but more frequently midway between these two 

 positions. In one of these subaqueous homes the Argyroneta 

 spends the greater part of the winter. I have had several 

 spiders which have remained in their nests under water for 

 three or four months, without either moving or taking food. 



