WATER SPIDEES AND WATER-WOEMS. 



273, 



When the female Argyroneta wishes to lay her eggs, she 

 either enlarges her old nest or bnilds an entirely new one. 

 The enlargement is ejffiected by spinning an addition of web 

 to its lower part, which she fills or inflates with air as soon 

 as it is completed. The male Spider often makes a new nest 

 for himself near to the one which his lady-love has constructed 

 or enlarged for her eggs. The eggs are enveloped .in a 

 kind of cocoon, which is fastened to the inside of the nest. 

 The yonng Spiders appear, according to the temperature of 

 the water, in about a fortnight. Almost directly they leave 

 the nest in which they have been bom, they begin to construct 



Fig. 164. Water-spider (Argyroneta aquatica) and Nest. 



small homes of web and air for themselves. Water-spiders 

 feed either upon terrestrial or aquatic animals; and for the 

 former they often leave the water. The Argyronetse while in 

 confinement may be provided with house-flies and small 

 aquatic insects. Their appetites, however, are very uncertain: 

 sometimes they wiU eagerly seize flies which have been thrown 

 to them, and drag them within their nests, soon to turn them 

 out again, sucked di-y of all their juices ; at other times they 

 will disregard all food, however tempting it may be. I am 

 sorry to say that these intelligent little creatures are occasion- 

 ally guilty of cannibalism. More than once I have noticed 

 that when several of them have been confined in the same 

 carefuUy-covered aquarium, their numbers have gradually 



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