THE CANADIAN ENTOMOLOGIST. 225 



author then refers to a communication made by him to Nature, vol. xv., 

 p. 7, 1877, on the same subject, and quotes from Figuier's Insect World 

 the following account of the pupation of Urticce : " The chrysalis, which 

 is shorter than the caterpillar, is at some distance from the silky net-work 

 to which it must fix itself; it is only supported by that extremity of the 

 caterpillar's skin which has not been split open. It has neither legs nor 

 arms, and yet it must free itself from this remaining part of the skin and 

 reach the threads to which it is to suspend itself. The supple and con- 

 tractile segments of the chrysalis serve for the limbs which are wanting to 

 it. Between two of these segments, as with a pair of pincers, the insect 

 seizes a portion of the folded skin, and with such a firm hold that it is able 

 to support the whole of its body on it. It now curves the hinder part 

 slightly and draws its tail entirely out of the sheath in which it was 

 enclosed,'' &c. Dr. Osborne then says : " How this can be conceived 

 possible, considering, the utterly soft condition of the newly-excluded 

 pupa, and that the caterpillar skin is now reduced to a packet so small 

 that it covers only the end of the tail of the chrysalis (loc. cit), in which 

 moreover there are no longer any free segments, I cannot understand. On 

 the other hand, it is very easy to show that the last and sufficient bond 

 of connection between the chrysalis and the old larva skin is a membrane 

 extending from the lining of the latter to the anterior horns of the two 



lateral ridges bounding the anal area of the chrysalis I have 



tested its strength to sustain the weight of the chrysalis and the time during 

 which it resists desiccation and the writhings of the insect, the obvious 

 object of which is, not to get rid of the old caterpillar skin, but to rupture 

 this membrane after the chrysalis has made good its tail attachment to the 

 silk." The communication in Nature called out no reply or remark from 

 lepidopterists, and hence Dr. Osborne again recited the facts in the Ent. 

 Mo. Mag. The Editors thereof say : " We will be very glad to know if 

 the very reasonable explanation advanced in support of the theory of our 

 correspondent has been elsewhere referred to, and also to have the results 

 of direct experiment by others. So far as we can discover, most of the 

 published accounts are simply copied, or extracted from Reaumur." 



As soon as I read this communication, I sought for butterflies of this 

 family, and soon took females of Grapta interrogations and D. archippus. 

 The former laid many eggs in a bag, tied over a stem of hop, and the other 

 a few on Asclepias. The larvae from both lots have finished their pupa- 

 tion, and I have carefully watched the process. Dr. Osborne's statement 



