236 



IgCIENTIFIC NOTES. 



Fecundation before Hybernation. — There seems to be a great 

 deal of doubt as to whether those species of Lepidoptera that hyber- 

 nate, pair in the autumn, or whether the sexes take no notice of each 

 other until the following spring. I have heard it remarked of some 

 Vanessa, that only the females hybernate, but I have myself found males 

 of most of them in the spring I have captured Vanessa polych oros 

 in copula in August on two or three occasions. Have any of our readers 

 facts on this subject ?— J. W. Tutt. December, 1890. 



PuPiE IN A Common Cocoon. — About the middle of last month 

 I opened nine or ten cocoons of Boinbyx trifolii, which I considered 

 overdue ; in one of these, in no way larger than the rest, I found two 

 pups pressed together. They appear to be females, and much smaller 

 than usual. This agrees with what Mr. G. M. A. Hevvett speaks of in 

 the case of the closely allied Eriogaster lanestris.—¥. B. Newnham, 

 Church Stretton, Salop. October, 1890. 



Disease as a Cause of Variation. — I have a strong opinion 

 that disease is, in some cases, the cause of many aberrations, 

 especially where the two sides of the insect do not coincide. To any 

 one who has bred lepidoptera in quantities (especially Macros), the 

 occurrence of holes (in the hind wings more generally) is a common 

 thing. That it is caused by injury before the msect emerges from 

 the pupa is evident, for were this not the case, the fluid (which, I 

 believe, causes the expansion of the wings) would exude through the 

 edges of the hole, as can readily be proved. I believe this to be the 

 liquid, which is afterwards exuded from the anus of the insect as a 

 drop of whitish, reddish, or chocolate-coloured fluid, and to be simply 

 the excess of moisture which is thus disposed of. — C. Fenn, Lee. 

 November, 1890. 



I should like to refer to the hole or malformation in the hind wing 

 of Mr. Robinson's aberrant, Orthosia upsiloti. Mr. Fenn is certainly 

 correct in saying that such holes are caused by injury before entering 

 upon the pupal stage. No doubt our artificial mode of breeding 

 increases the danger of such malformations, and of cripples generally, 

 but that such do occur at large now and then, a specimen of 

 O. viacilenta which I took at ivy this season, will show. This 

 example has two holes, one large, the other small, both round and 

 separated by wing nervures. The microscope shows the edges of 

 the holes to be quite smooth, and there is little or no disturbance of 

 the scales. The malformation (with a concave piece of the hind 

 wings absent) which takes place in the hind wings of Liparis dispar, 

 appears to be of very frequent occurrence, and I once bred a 

 specimen of the large American Bombyx, — A. polyphonies — with the 

 wings deeply indented in the same way. — G. C. Griffiths, Clifton, 

 Bristol. November, 1890. 



There seems very little doubt in my mind, that most malformations 

 become absolutely fixed at the moment that the larva becomes changed 

 to a pupa. Any one, who has had the good fortune to observe an 

 insect at this point, would immediately be struck with the fact that, at 

 the final larval exuviation, the external organs of the imago in their 

 rudimentary form are perfectly formed and shaped, and that the larva 



