MEANS OF DEFENCE OF CATERPILLARS, 191 



tlie two preceding' insects, thisf!;rub is also most unex- 

 pectedly transformed into a very pretty green beetle, 

 of the form of a tortoise, the wing-cases of which 

 project all round as a covering for the legs. 



A C 



A. Cassicla equestris. B, its grnh, magnified to shew its anal 

 forks. C, the same with its canopy of excrements. 



The larvae of the golden-«yed fly {Chrysopa perla^ 

 Leach), whose very singular eggs we formerly men- 

 tioned, covers itself with the fragments of the apliides 

 which it has devoured, — a moving sepulchre of dry 

 bones*. 



A very familiar instance of this mode of defence 

 occurs in the larva of the cuckoo-spit frog-hopper 

 {Ttttigonia spumaria, Olivier), so frequently seen 

 in summer on willows, rose-trees, lychnis, grass, and 

 other plants. This creature is of an exceedingly soi>. 

 structure ; and it is probably, therefore, as a protection 

 from the sun, that it throws up all around it the little 

 tuft of white froth, called, from a popular mistake, 

 cuckoo-spit. The perfect insect is covered with hard 

 wing-cases, of a brown colour, with a white spot and 

 pale double band. 



It would appear that the hair, which we have de- 

 scribed above as covering the bodies of some cater- 

 pillars, is partly intended by Nature to defend them 

 from cold during the winter. The truth of this 

 * Reaumur, iii. 380, &c. 



