280 MOTIONS OF INSECTS. 



nera of the Tipidarice it belongs, nor is it referred to 

 by Meigen. 



I come now to the jumping apodes, and one of this 

 description will immediately occur to your recollection, 

 — that I mean which revels in our richest cheeses, and 

 produces a little black shining fly [Tyrophaga Casei). 

 These maffgots have long been celebrated for their sal- 

 tatorious powers. They effect their tremendous leaps — 

 laugh not at the term, for they are truly so when com- 

 pared with what human force and agility can accom- 

 plish — in nearly the same manner as salmon are stated 

 to do when they wish to pass over a cataract, by taking 

 their tail in their mouth, and letting it go suddenly. 

 When it prepares to leap, our larva first erects itself 

 upon its anus, and then bending itself into a circle by 

 bringing its head to its tail, it pushes forth its unguiforni 

 mandibles, and fixes them in two cavities in its anal tu- 

 bercles. All being thus prepared, it next contracts its 

 body into an oblong, so that the two halves are parallel 

 to each other. This done, it lets go its hold with so 

 violent a jerk that the sound produced by its mandibles 

 may be readily heard, and the leap takes place. Swam- 

 merdam saw one, whose length did not exceed the fourth 

 part of an inch, jump in this manner out of a box six 

 inches deep; which is as if a man six feet high should 

 raise himself in the air by jumping 144' feet ! He had 

 seen others leap a great deal higher ^. The grub of a 

 little gnat lately noticed {Chironomus stcrcorarius) has a 

 similar faculty, though executed in a manner rather dif- 

 ferent. These larva?, which inhabit horse-dung, though 

 deprived of feet, cannot move by annular contraction 

 » Swamm. Bibl. Nal. Ed. Hill, ii. 64. b. 



