228 



MOTIONS OF INSECTS. 



doubled as it were in two, against the sides of ditches or the 

 stalks of aquatic plants. If it is placed in a glass half full 

 of water, it so fixes itself against the sides of it, that its head 

 and tail are in the water while the remainder of the body is 

 out of it ; thus assuming the form of a siphon, the tail end 

 being the longest. When this animal is disposed to feed, it 

 lifts its head and places it horizontally on the surface of the 

 water, so that it forms a right angle with the rest of the 

 body, which always remains in a situation perpendicular to 

 the surface. It then agitates, with vivacity, a couple of 

 brushes, formed of hairs and fixed in the anterior part of the 

 head, which, producing a current towards the mouth, it makes 

 its meal of the various species of animalcula, abounding in 

 stagnant waters, that come within the vortex thus produced. 

 As these animals require to be firmly fixed to the substance 

 on which they take their station, and their back is the only 

 part, when they are doubled as just described, that can apply 

 to it, — they are furnished with minute legs armed with black 

 claws, by which they are enabled to adhere to it. They have 

 ten of these legs : the four anterior ones, which point towards 

 the head and are distant from each other, are placed upon the 

 fourth and fifth dorsal segments of the body ; and the six 

 posterior ones, which point to the anus and are so near to 

 each other as at first to look like one leg, are placed on the 

 eighth, ninth, and tenth. When the animal moves, the body 

 continues bent, and the sixth segment, which is without feet, 

 and forms the summit of the curve, goes first. 1 De Geer 

 named the fly it produces Tipula amphibia : it seems not 

 clear, from his figure, to which of the modern genera of the 

 Tipularice it belongs ; nor is it referred to by Meigen. 



I come now to the jumping apodes ; and one of this de- 

 scription will immediately occur to your recollection, — that I 

 mean which revels in our richest cheeses, and produces a little 

 black shining fly {Tyropliaga Casei). These maggots have 

 long been celebrated for their saltatorious powers. They 

 effect their tremendous leaps — laugh not at the term, for 

 they are truly so when compared with what human force and 



1 De Geer, vi. 380. t. xxiv. f. 1 — 9. Mr. Westwood refers this insect to the 

 modern genus Dixa. {Mod. Class, ii. p. 527.) 



