82 BRITISH LEPIDOPTEBA. 



noticed a difference between the dark larvae beaten from oak and 

 birch corresponding with the difference between the twigs on which 

 the larvae rest in the two cases. Wilson beat a larva of this species 

 from a lichen-covered food-plant, that so exactly resembled the lichen, 

 that he thought the larva must be that of another species, until the 

 moth appeared. 



The longitudinal lines of the larva of Panolis piniperda make it 

 almost invisible when hiding among the needles of the Scotch fir. 

 The larva of Anarta myrtilli, with its intricate crossing and recrossing 

 of lines, is scarcely discernible when resting on a heather twig. The 

 larva of Anticlea cucullata (sinuata) is scarcely to be detected on the seed- 

 heads of Galium veruin, nor that of Cidaria sayittata on those of Tka- 

 lictnim Jlavum, so close is their resemblance to their respective food- 

 plants, when at rest. Even the large hairy larva of Eutricha qut'iri folia, 

 when motionless on its food-plants sallow, hawthorn, blackthorn 

 and buckthorn is so difficult to detect, that the usual way of finding 

 it, on Wicken Fen, where the species is abundant, is to run the hand 

 down the stems to feel for it. 



Besides instances, such as those just quoted, of special protective 

 resemblance between a larva and its own particular food-plant, a 

 general protective resemblance, due to a general harmony between the 

 object and its surroundings, is often to be observed. It seems almost 

 impossible to understand how there can be a general harmony between 

 some large and apparently conspicuous larvae and their food-plants, 

 when one considers them apart from each other, but when one sees 

 for the first time, the larva of Deilepliila enjiJiorbiae or J'apilio machaon 

 on its food-plant in a state of nature and surrounded by those plants 

 that make up its natural environment, one is no longer struck with 

 the difficulty often experienced in a first search for the larva, and 

 recognises that, in the blending of the various tints of the plants 

 around it, the fitness of the colours of the caterpillar, for its effectual 

 concealment, is very evident. In such cases as these, the larva does 

 not resemble any one particular piece of the food-plant, but the general 

 character of the larva mimics or resembles the general environment, 

 whilst special parts of the larva represent special objects in the en- 

 vironment. 



One of the best examples of this general protective mimicry is 

 afforded by the larva of Charaj-es jasiw. This larva rests on the upper 

 surface of a leaf of Arbutus unedo (or on a bunch of leaves fastened 

 together with silk), basking in the sun by day, and always fully exposed. 

 One might suppose from this, that the larva would be very conspicuous, 

 yet, on the contrary, it is difficult to detect. Chapman says (tint. 

 Record, ix., p. 193) : The larva at rest, seen from whatever direction, 

 exactly imitates some aspect of leaves or buds under the different 

 effects of light and shade, and it is thus possible for an untrained eye, 

 in many instances, to look at it, and for it, for some time before seeing 

 it. The yellow lateral line resembles the mid-rib of the leaf seen from 

 above or below, according to light ; the colour and apparent texture of 

 the skin are the same as those of many leaves. The extraordinary 

 head, with its coloured jaws and spines, suggests in many aspects, the 

 little group of buds at the extremity of the branches. One has often 

 to look a second time at certain leaves and branches, as well as at the 

 buds, to be sure that they are parts of the tree, and not a larva. The 



