278 THE COLOUKS OF ANIMALS 



tected larvaB are often those which die in the largest 

 numbers from the attacks of enemies. The excep- 

 tional standard of defence has been only reached 

 through the pressure of an exceptional need. 



The larva of Lobster Moth well concealed by Special 

 Protective Resemblance 



The caterpillar which I select as a second example 

 of the way in which various modes of defence may be 

 combined, is that of the Lobster Moth {Stauropus 

 fagi), which is rare in this country. Its usual food- 

 plant is beech, and when at rest it is well concealed 

 by resembling a withered leaf irregularly curled up. 

 The stalk is represented by two long thin appendages, 

 which, like the fork of the Puss caterpillar, have been 

 modified from the last pair of claspers. At rest, these 

 appendages are held together and appear to be one. 

 The second and third pairs of true legs are extra- 

 ordinarily long, but the length of each is halved by 

 doubling in the middle, and all four doubled-up legs 

 hang down in a bunch. They thus resemble in the 

 most remarkable manner the bunches of brown scales 

 (the stipules of the foliage leaves) which enclose the 

 buds of the beech, and hang down after the latter are 

 unfolded. The colour, length, and shape of each 

 folded leg, and the number of legs which thus hang 

 down together, are all such as strongly to suggest the 

 appearance of the scales. 



