396 HISTORY OF 



make themselves lodgments of cements, which they fasten to some 

 solid body at the very bottom of the water, unless, by accident, 

 they meet with a piece of chalk, which being of a soft and pliant 

 nature, gives them an opportunity of sinking a retreat for them- 

 selves, where nothing but the claws of a eray-fish can possibly 

 molest them. The worm afterwards changes its form. It ap- 

 pears with a large head, and a tail invested with hair, and mois- 

 tened vi^ith an oleaginous liquor, which she makes use of as a 

 cork to sustain her head in the air, and her tail in the water, and 

 to transport her from one place to another. When the oil with 

 which her tail is moistened, begins to grow dry, she discharges 

 out of her mouth an unctuous humour, which she sheds all over 

 her tail, by virtue whereof she is enabled to transport herself 

 where she pleases, without being either wet or anywise incom- 

 moded by the water. The gnat, in her second state, is, properly 

 speaking, in her form a nymph, which is an introduction or 

 entrance into a new life. In the first place, she divests herself 

 of her second skin ; in the next, she resigns her eyes, her anten- 

 nae, and her tail ; in short, she actually seems to expire. How- 

 ever, from the spoils of the amphibious animal, a little winged 



cccds ia the same manner to add egg after egg in a vertical (not a horizon- 

 tal) position, carefully regulating the shape by her crossed legs ; and as her 

 raft increases in magnitude, she pushes the whole gradually to a greater 

 distance, and when she has about half-finished, she uncrosses her legs and 

 places them parallel, the angle being no longer necessary for shaping the 

 boat. Each raft consists of from two hundred and fifty to three hundred and 

 fifty eggs, which, when all laid, float on the water secure from sinking, and 

 are finally abandoned by the mother. They are hatclied in a few days, the 

 grubs issuing from the lower end ; but the boat, now composed of the empty 

 shells, continues to float till it is destroyed by the weather. 



" Kirby justly describes this little vessel as resembling a London wherry, 

 being sharp and higher, as sailors say, fore and aft, convex below and con- 

 cave above, and always floating on its keel. ' The most violent agitation of 

 the water,' he adds, ' cannot sink it, and what is more extraordinary, and a 

 property still a desideratum in oiir life-boats, though hollow, it never be. 

 comes filled with water, even though exposed. To put this to the test, I 

 placed half a dozen of these boats upon the surface of a tuml)ler half-full of 

 water : 1 then poured upon them a stream of that element from the mouth 

 of a quart bottle held a foot above them. Yet after this treatment, which 

 w.is so rough as actually to project one out of the glass, I found them float- 

 ing as before upon their bottoms, and not a drop of water within their ca- 

 vity.' We have repeatedly pushed them to the bottom of a glass of water ; 

 but they always came up immediately to the surface apparently un wetted.' 

 —Insect Transformations. 



