THE WATER SPIDERS. 273 



Many years ago, as a child, I used to watch the 

 Water Spiders diving into the dark, still pools with 

 which the Cherwell abounds, and to wonder where 

 they could be going with their glittering suit of 

 bubbles. As far as I know, when it dives without 

 the large air-bubble, it is either in search of prey or 

 going home. But, when it carries the large bubble 

 within its hind-legs, it is engaged in supplying its 

 subaquatic home with air. Briefly told, this is the 

 story of its home : 



The female Spider, when she is about to lay her 

 eggs, dives to some depth, and searches for a suitable 

 locality among the submerged portions of aquatic 

 vegetation. She then spins an oval cocoon, shaped 

 very much like an empty egg-shell with the end cut 

 off, and having the opening downwards. Having 

 completed this task, she then ascends to the surface, 

 takes down a large bubble of air in the manner that 

 has already been described, and, still laden with it, 

 enters the cocoon. She then releases the bubble, 

 which rises to the top of the cocoon, which is air- 

 tight, and, of course, expels a corresponding quantity of 

 water. Several similar journeys then take place, and in 

 a short time the cocoon is filled with air, and becomes 

 a subaquatic chamber in which the Spider can live. 



Perhaps some of my readers may remember the 

 old diving-bells. In the present bells a constant 

 supply of air is kept up by means of pumps anc* 

 tubes; but in the older bells no such plan was 

 adopted. A quantity of air was forced into strong ves- 

 sels, which were lowered by ropes to the bell. The 

 divers then took the vessels into the bell, and set the 



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