10 THE ENTOMOLOGIST. 



instance by the purest "fluke." Many years ago I remember 

 meeting with a full-grown caterpillar of the common " riband 

 wave " {Ptf/chopoda aversata) crawling on a tree-trunk in Epping 

 Forest, probably searching for a place in which to pupate. And 

 thrice more recently, when prying about amongst a mixture of 

 low-growing plants on rough broken ground, such as that around 

 the " Limpet Kun " at Sandown, I have happened upon a larva 

 which has been successfully bred, the three species being P. in- 

 terjectaria, Leptomeris imitaria, and L.marginepunctata. Yet all 

 these four species, and several others in the genus, are really 

 quite common — either everj^where, as in the case of P. aversata, 

 or locally, as in that of the other three. Hence it is pretty clear 

 that their small size and retiring habits— the latter including the 

 fact that they all, or nearly all, feed upon insignificant growths 

 close to the ground, shield them sufficiently from human obser- 

 vation ; and were it not that the eggs are easy to obtain from a 

 captured female, and the larvae not hard to rear, we should probably 

 know comparatively very little about their early stages. It is 

 only right to add, however, that a few entomologists, such as 

 Dr. Eossler, of Wiesbaden, seem to have been exceptionally 

 gifted at finding obscure larvae in their native haunts, and have 

 given us records of the habits and habitat of quite a respectable 

 number of the species. 



If, however, I cannot say much about icheii the larvae are 

 " found," I can tell you definitely when they are, or theoretically 

 should he,Ji7idahle. And this is throughout ten or eleven months 

 of the year — almost any time, excepting, say, June or July (when 

 practically all the imagines are out). For this is a genus, or 

 group, of clearly-defined habit as regards the general course of 

 its life-cycle. I remember hearing my friend Mr. Bacot tenta- 

 tively suggest a fixed hybernating stage as a possible generic 

 character — i.e., mark of close phylogenetic relationship — in 

 certain cases amongst the Lepidoptera. Of course neither he 

 nor I would overpress it ; for it is well known that sometimes the 

 very closest allies differ in this respect, so that it would even 

 seem as though the physiological isolation which formed them 

 into species were actually due to an initial divergence in the 

 hybernating habit ; e.g., Cidaria immanata passes the winter as 

 an egg, its twin brother C. truncata as a larva. But it is none 

 the less true that several thoroughly natural groups have main- 

 tained complete uniformity, so that we find all the Acronyctae, 

 all the Dianthceciae, &c., hybernating as pupae, all the great 

 genus Agrotis as larvae, and so on. Now our ' Acidalia ' seem ab- 

 solutely incapable of hybernating in any other state than that of 

 caterpillar, and the apparent inflexibility of this rule in so large 

 a group seems at least worthy of mention. I noticed that the 

 Ptev. G. H. Raynor commented on the fact in a recent number of 

 the ' Entomologist's Record ' (vol. xvi. p. 108) ; but, misled by 



