30 



shell, but waiting for the spring before it bursts its bonds. The 

 eggs of Lijmantria monacha, for example, may be seen to contain 

 the fully-formed larvas in September, yet they do not emerge until 

 the following March or April. From this it is but a step to the 

 state of things exhibited by certain Fritillary Butterflies, the young 

 larva of Vnjaa [Aigynnifi) paphia (20), for example, emerging from the 

 egg in July, enters at once into hibernation after devouring the empty 

 egg-shell from which it has hatched. Many other larvae pass the 

 winter while still young, e.i/., Liinenitis ^ibilla, Abraxas ipossulcuiata, 

 etc., others when half or nearly full grown, until finally, as in the 

 case of Macrot/ii/lacia riibi, they hibernate as fully-fed larvae that do 

 not feed again after waking from their long winter sleep, though 

 they drink greedily, and take full advantage of whatever sunshine 

 there may be, before spinning up to pupate. I am not aware of 

 any lepidopterous larvae, at any rate in this country, that pass the 

 winter in a prepupal state within their cocoons, waiting until the 

 spring before the moult takes place, but such is commonly the case 

 m the Hymenoptera, at least in the aculeate and the phytophagous 

 divisions of the order. 



In certain Zyijaena larvas Burgeft' (3) has shown that the 3rd or 

 4th moult produces a special hibernating instar in which the larva 

 takes no food, its colours are dull, the size of the head is even 

 smaller than that of the previous stage, the contents of the body 

 are viscous, and particularly resistent to drought, and the larva 

 enters at once into hibernation. When it wakes up in the spring 

 it drinks greedily, increasing in size, and soon moults again, 

 resuming its normal colours before commencing to feed again. In 

 these larv* there is therefore a special hibernating stage during 

 which no food is taken, and showing definite structural characters, 

 sharply defined by a moult before and after hibernation. This 

 special stage appears to be intercalated between the normal larval 

 instars rather than to be a normal instar completely given up to the 

 purpose of hibernation. 



The larva of the beetle Driliis flavescenn, which feeds upon 

 snails, also assumes a special form for hibernating purposes very 

 different from the active predatory form. Some Zi/ffaenidae show 

 a further interesting phenomenon in that some larvfe, after hiber- 

 nation, will feed up rapidly, and produce moths in the ensuing 

 summer, while others of the same brood will remain small, and 

 eventually hibernate a second time before attaining the perfect 

 state. In this latter case Burgeff was unable to recognise a definite 



