HABITATIONS OF INSECTS. 



401 



prey, plunges with it to the bottom of the water. Here it is 

 she forms her singular and unique abode. She would evi- 

 dently have but a very uncomfortable time were she con- 

 stantly wet, but this she is sagacious enough to avoid ; and 

 by availing herself of some well-known philosophical prin- 

 ciples, she constructs for herself an apartment in which, like 

 the mermaids and sea-nymphs of fable, she resides in comfort 

 and security. The following is her process. First she spins 

 loose threads in various directions attached to the leaves of 

 aquatic plants, which may be called the frame-work of her 

 chamber, and over them she spreads a transparent varnish 

 resembling liquid glass, which issues from the middle of her 

 spinners, and which is so elastic that it is capable of great 

 expansion and contraction ; and if a hole be made in it, it 

 immediately closes again. Next she spreads over her belly 

 a pellicle of the same material, and ascends to the surface. 

 The precise mode in which she transfers a bubble of air be- 

 neath this pellicle is not accurately known; but from an 

 observation made by the ingenious author of the little work 

 from which this account is abstracted, he concludes that she 

 draws the air into her body by the anus, which she presents 

 to the surface of the pool, and then pumps it out from an 

 opening at the base of the belly between the pellicle and 

 that part of the body, the hairs of which keep it extended. 

 Clothed with this aerial mantle, which to the spectator seems 

 formed of resplendent quicksilver, she plunges to the bottom, 

 and, with as much dexterity as a chemist transfers gas with 

 a gas-holder, introduces her bubble of air beneath the roof 

 prepared for its reception. This manoeuvre she repeats ten 

 or twelve times, until at length in about a quarter of an hour 

 she has transported as much air as suffices to expand her 

 apartment to its intended extent, and now finds herself in 

 possession of a little aerial edifice, I had almost said an en 

 chanted palace, affording her a commodious and dry retreat 

 in the very midst of the water. Plere she reposes unmoved 

 by the storms that agitate the surface of the pool, and de- 

 vours her prey at ease and in safety. Both sexes form these 

 lodgings. At a particular season of the year the male quits 

 his apartment, approaches that of the female, enters it, and 

 VOL. I. r> D 



