CONDITION OF LACHNEIS LANESTRIS DURING THE PUPAL STATE. 285 



dead, eleven contained pupas that were entirely undeveloped, i.e., with 

 translucent pale tissues, just as shortly after pupation, the other 

 eleven contained puppe more or less developed. In the case of one of 

 these I extracted the imago from the pupa-case, and it seemed fully 

 developed, except that the hairs on the general surface seemed sparse, 

 but this was probably a delusive appearance due to their being wet 

 and agglutinated. This moth was unquestionably alive, and I imagine 

 the other ten of this group are so also. Clearly we want some more 

 observations on this subject. Mr. Russell and myself Avill try to 

 follow out the further history of these 21 cocoons, but opening the 

 cocoons and so removing the protection they afi'ord the pupro, not so 

 much against predaceous foes, mites, &c., as against excessive variations 

 of moisture, has no doubt much prejudiced further success with them, 

 as they will probably either dry up or mould off. Will any other 

 undeveloped ones emerge next spring, or are the developed ones those 

 that intend to do so, if so, why do they develop so early, whilst larvse 

 of the season are still feeding, and should we have found them quite 

 undeveloped last April ? When do larvfe now spinning up and 

 meaning to emerge next March begin imaginal devolopment ? These 

 ten pupje could obviously emerge this autumn so far as the advance 

 they have made in development is concerned. 



On September 2nd I received from Germany a consignment of 

 cocoons of L. lanestris, stated to be this season's cocoons, and I see no 

 reason to doubt that they are so. Of these, eleven were dead, being 

 detected by their lightness. Some double cocoons contained either 

 dead larvae or pupje, or pupaB deformed by pressure against the other 

 occupant. Of the sound ordinary cocoons I opened 45, and these 

 present 48 pupae in which development is more or less advanced, 

 in some only the darkening of the eyes has occurred, in others 

 greater or less general o]Dacity, most noticeably of the wings, is 

 observed, whilst in some more or less coloration has already taken place, 

 and in a few the imaginal markings are quite evident. In only two 

 cases are the pupae still unchanged. These pupa are from the same 

 source as those of last year. Those it will be remembered gave only one 

 pupa going over to a second year out of a large number, and therefore I 

 presume are of a race or from a climate in which " going over " is a 

 much less common phenomenon than with the British form. As 

 regards those I opened, it is to be noticed that I left a number of 

 cocoons untouched, and that those I opened included nearly all those 

 of a somewhat delicate texture. The delicate, flimsy (comparatively) 

 texture of cocoon is probably due to a weaker constitution of the larva 

 as a rule, but it may also have some correlation with an intention to 

 pass as short a time as possible in the pupal state. I have already 

 expressed a fear that opened coocons will not have a good chance of sur- 

 viving to enable one to complete the observation, and I have therefore left 

 a number unopened to be examined after the emergence next spring. 

 As an interim conclusion, founded on Mr. Russell's cocoons and these 

 before me now, it would seem that development of the imago within 

 the pupa, occurs during the summer and autumn, and that the moths 

 emerging in the spring are fully developed in their chrysalids when 

 winter sets in. These German cocoons are obviously spun up much 

 earlier than is usual with our English ones. The German ones, there- 

 fore, have a full autumn and a scrap even of summer in which to 



