ON THE PALPICORNES. 437 



longer possible for me to distinguish the movements of the 

 spinneret. In the mean time some small bubbles of air com- 

 menced to escape from the interior of the shell ; I thought 

 that it was the eggs which occasioned this displacement ; in 

 fact, at the moment in which the hydrophilus removed its 

 abdomen from the extremity of its elytra, I approached to 

 it a strong magnifier, and I perceived distinctly small oblong 

 and whitish bodies, which were placed side by side, and 

 which the spinnerets gradually covered with a white and 

 transparent fluid. In three quarters of an hour the busi- 

 ness of laying was over. The insect withdrew its abdomen 

 by little and little from the under part of the leaf, closed 

 its shell rather imperfectly, and assumed a new position. 



It remained for it to form the point which terminates this 

 shell. To bring this about, the hydrophilus, always having the 

 head underneath, brought back its hinder legs on the leaf, 

 and placed them on each side of the shell. The elytra, the 

 extremity of which was on a level with the water, were 

 removed from the abdomen, and passed, by some lines, the 

 anus, which was very much dilated. The spinnerets were 

 no longer concealed by any thing. One might easily follow 

 all their movements ; those were continual and rapid. It 

 required, however, more than half an hour for the hydro- 

 philus to form this point. The insect carried here and there, 

 above the shell, and on the edge of the leaf, a slender and 

 yellowish thread, which, at the very instant, acquired some 

 degree of firmness. Speedily new layers were applied on 

 the first, and as the last always exceeded the preceding by 

 some lines, there was insensibly formed a slender and coni- 

 cal appendage, of a citron-yellow colour, which was raised 

 about an inch above the surface of the water. This labour 

 being achieved, the hydrophilus directed its spinneret 

 lightly, from top to bottom, along the point, and bringing 

 back by degrees, its entire body vmder the water, it aban- 



