INSECTS. 
1C7 
the bottom, where they are speedily hatched. The larva 
is a somewhat uncouth, broad, and flat, olive-coloured 
animal, rather spider-like, having six sprawling legs, which 
crawls about tho mud at the bottom of ponds, or glides 
by a singular mechanism through their waters. The 
hinder extremity of the body is furnished with several 
leaf-like processes, capable of being brought closer toge- 
ther, or opened at pleasure. These close the orifice of a 
cavity, whose sides are very muscular. When the Insect 
wishes to move rapidly, it opens this cavity, which thus 
becomes filled with water ; then, by a contraction of the 
walls of the cavity, the water is forcibly ejected in a stream 
as from a syringe ; ahd, by the re-action produced by the 
impact of the jet d'eau upon the surrounding fluid, the 
creature shoots ahead, with its legs closely packed along 
its sides. 
But the most singular part of its structure is its face. 
“ Conceive,” says the graphic and eloquent Kirby, “ your 
under lip to be bony instead of fleshy, and to be elongated 
downwards, so as to wrap over your chin, and extend to 
its bottom ; that this elongation is then expanded into a 
triangular convex plate, attached to it by a joint, so as to 
bend upwards again, and fold over the face as high as the 
nose, concealing, not only the chin and the first-mentioned 
elongation, but also the mouth and part of the cheeks : 
conceive, moreover, that to tho end of the last-mentioned 
plate are fixed two other convex ones, so broad as to cover the 
whole nose and temples ; that these can open at pleasure 
transversely like a pair of jaws, so as to expose the nose and 
mouth, and that their inner edges, where they meet, are 
