264 



INSECT TRANSFORMATIONS. 



spreads. I once observed a cheese which I had 

 purposely exposed to this kind of fly grow moist in a 

 short time in those parts of it where eggs had been 

 deposited, and had afterwards been hatched into 

 maggots ; though, before, the cheese was perfectly 

 sound and entire."* 



The cheese-hopper is furnished with two homy 

 claw-shaped mandibles, which it uses both for digging 

 into the cheese and for movnig itself, being destitute 

 of feet. Its powers of leaping have been observed by 

 every one ; and Swammerdam says, " I have seen 

 one, whose length did not exceed the fourth of an 

 inch, leap out of a box six inches deep, that is, twenty- 

 four times the length of its own body : others leap a 

 great deal higher, "f For this purpose it first erects 

 itself on its tail, which is furnished with two wort- 

 like projections, to enable it to maintain its balance. 

 It then bends itself into a circle, catches the skin 

 near its tail with its hooked mandibles, and after 

 strongly contracting itself from a circular into an ob- 

 long form, it throws itself with a jerk into a straight 

 line, and thus makes the leap. 



Cheese-hoppers (Pinphila casei. Fallen), a, the maggot ex- 

 tended ; 6, iti a leaping position ; d, the same magnified ; e, the 

 fly magnihed ; /, ^f, the fly, natural size. 



One very surprising provision is remarkable in 

 the breathing-tubes of the cheese-maggot, which are 

 '^' Swammerdam, vol. ii. p. 69. f Bibl. Nat-, vol. ii. p. 65. 



