102 



The Naturalist. 



A popular writer, the Rev. J. G. Wood, whose works are perhaps 

 more justly esteemed for being entertaining than for depth or 

 accuracy, remarks that the caterpillar of the puss moth {Cerura vinula) 

 " boldly fixes its residence on the exterior of the tree on which it 

 feeds, trusting to its similitude to the bark for concealment." This is 

 a remarkable proposition ; for however identical in hue may be the 

 cocoon to the bark of the tree upon which the caterpillar has livedo we 

 can hardly imagine the colour of the cocoon to be exactly a matter of 

 choice, any more than the colour of the larva itself. 



The similarity in colour between many caterpillars and the plants 

 upon which they feed is very remarkable, and I think not to be easily 

 explained, as we must bear i^ mind that the theories of natural 

 selection do not seem applicable to insects in a state of immaturity, 

 and whose existence is perpetuated through a totally different form, 

 possessing very different powers and instincts, and also as a rule 

 totally different in colours. For it is a singular fact that, while the 

 gayest coloured caterpillars produce the dullest of moths, so the most 

 dark and dingy caterpillars develop into the most gorgeous butterflies. 



In some cases the cause of the colour of the caterpillar is evident, as 

 in the larvae of GucuUia aster is, which feeds upon the flowers of the 

 China aster. I have noticed that those feeding on the petals of the 

 flower were pink or purple in colour, while those feeding on the 

 leaflets outside the blossom were green ; but no difference was 

 observable in the hue of the moths developed. One of the geometers, 

 Ellajna fasciaria, which is a silvery green, with longitudinal stripes, 

 exactly resembles the leaves of the Scotch pine on which it feeds. 

 Another small brown caterpillar, with transverse stripes of darker and 

 lighter brown, with two prominent tubercles on each segment, and 

 rows of smaller tubercles, resembles quite as closely the orange- 

 coloured young cones, with their filmy covering, that grow at the ends 

 of the small branches of the same tree. 



The larvae of Jnarta myrtilli are very difficult to find, from their 

 close resemblance to the young shoots of heather on which they feed, 

 while those of Smerinthus ocellatus, the eyed-hawk moth, pale green 

 with transverse white lines, exactly reproduce a segment of the veined 

 leaf of the sallow. 



The caterpillar of Acherontia Atropos, the " death's head moth," is 

 usually of a pale green colour, with a series of purple, yellow, and 

 white streaks on its sides, and it is noticeable how nearly these colours 

 approach to those of the blossoms of the potato-plant, on the leaves of 



