WATER-INSECTS. 251 



The one now referred to began to weave its beautiful web 

 about five o'clock in the afternoon. After much preliminary 

 preparation^ it ascended to the surface, and obtained a bubble 

 of air, with which it immediately and quickly descended ; and 

 the bubble was disengaged from the body, and left in con- 

 nection with the web. As the nest was on one side, in con- 

 tact with the glass, enclosed in an angle formed by t\Yo leaves 

 of the Stratiotes, I could easily observe all its movements. 

 Presently it ascended again, and brought down another bub- 

 ble, which was similarly deposited. In this way no less 

 than fourteen journeys w'ere performed ; sometimes two or 

 three very quickly, at other times wath a considerable in- 

 terval between them ; during wdiich the little animal was 

 employed in extending and giving shape to the beautiful 

 transparent bell, getting into it, pushing it out at one place, 

 and rounding it at another, and strengthening its attach- 

 ment to the supports. At length it seemed to be satisfied 

 with its dimensions, when it crept into it, and settled itself 

 to rest. 



"No. 3. The only difference between the movements of 

 this and the former w^as, that it was rather quicker in form- 

 ing its cell. In neither vessel was there a single bubble of 

 oxygen evolved by the plant. The manner in which the 



