154 INSECT TRANSFORMATIONS. 



but Rosel's figure, which we here copy, is more ac- 

 curate. 



Looking at these very singular forms of caterpil- 

 lars, we could not anticipate, without previous know- 

 ledge, that all of them produced insects of nearly the 

 same shape, though differing considerably in size and 

 colour. It is not a little remarkable, also, that the 

 colours of caterpillars, with a few exceptions, such as 

 the magpie moth (Mraxas grossulariata), are very 

 different indeed from the insects into which they are 

 transformed. Plain and inconspicuous caterpillars 

 will sometimes give splendidly coloured insects, as in 

 the case of the Vanessa butterflies; while finely mark- 

 ed caterpillars will give plain insects, as the one whose 

 gaudy stripes of sky-blue, scarlet, and black, has ob- 

 tained it the appropriate name of the lackey ( Clisio- 

 campa neustria, CURTIS), though the moth is of a 

 dull brownish yellow. Two of our finest native in- 

 sects, however, the swallow-tailed butterfly and the 

 emperor-moth, are produced from beautifully coloured 

 caterpillars; but neither the colours nor the .markings 

 of these have any resemblance. 



A more extraordinary difference, however, between 

 the first and the last stage of insect life occurs in the 

 case of those insects whose larvse are aquatic. One 

 of our commonest families of insects, the gnats (Cw- 

 licidce, LATR.), whose ingenious mode of construct- 

 ing a floating raft of eggs we have already described, 

 affords a very striking illustration of our position. 

 When these eggs are hatched, the grubs appear; but 

 they do not, as is said by older naturalists, < make 

 themselves little lodgments of glue, which they fasten 

 to some solid body at the very bottom of the water, 

 unless they meet with chalk, whose softness permits 

 them to burrow into its substance.'* On the contra- 



* Spectacle de la Nature, i, 123. 



