INFANCY OF CRABS AND CATERPILLARS 245 



But in some cases, advertisement, not concealment, seems 

 to be sought, as when the body is marked by alternate 

 rings of black and yellow — as in the caterpillar of the 

 cinnabar moth, for example — or when the body is cut up 

 into alternating bands of black and red, as in the case of 

 the wood-tiger moth. In all such cases it is found that 

 such larvae are unpalatable, and will be refused by birds 

 and other insect-eating creatures. The garish colouring 

 seems to warn the prospective eater that the attempt will 

 be followed by disagreeable results ! The one device is as 

 effective as the other. Spines and long hairs, as in the case 

 of the " woolly bear," the larva of the tiger-moth, form an 

 equally effective protection ; though nevertheless not an 

 absolute defence, since the cuckoo preys greedily thereon, 

 and its stomach, in consequence, is matted with the hairs. 

 But this is the only bird which will touch them. 



But yet other devices are to be found calculated to 

 save the exhibitor from being eaten. Take, for instance, 

 the case of the larva of the puss-moth. Herein the body 

 is green enlivened by bars of red on each side of the head, 

 and a broad black band, bordered by a narrow white line 

 down the back. But this is not all. The tail ends in a 

 pair of short rods formed by transformation of the last 

 pair of legs ; and from these, when the creature is alarmed, 

 a pair of long red filaments are thrust, and waved rapidly 

 about, the whole body at the same time being thrown 

 into a most wooden and " unnatural " attitude. Evi- 

 dently this combination of colour and jugglery serves as 

 a useful deterrent where too curious birds or other insect- 

 eating creatures are about. But this device is used only 

 by the young larvse. 



By the time they have reached what we may call middle 

 age in larval life they lose the power of thrusting out the 



