| OCR Text |
Show 12 MR. H. J. ELWES ON THE GENUS PARNASSIUS. [Jan. 19, torpid without flying; that the duration of the act is from 32 to 6| hours, but the pouch is developed in a much shorter time, thirty minutes in one case sufficing to make it visible to the naked eye. But my observations of P. mnemosyne make it evident that either that species differs from P. apollo in this respect, or that instances of imperfect copulation, not followed by the appearance of a pouch, may occur. Mr. Thomson also proves : -That eggs may be and are sometimes laid before the completion of the act, and that they may be laid by pouehleFs females of P. apollo, as I found was also the case with P. mnemosyne. That laying continues for several days at intervals, the life of the female extending to at least a week, whilst the males appear completely exhausted by the act of copulation, and die in one or two days after it without flying much, though they remain lively and strong for several days before the act takes place. No attempt was made by virgin males observed by Mr. Thomson to mate with an alreadv mated female, but m y own observations in nature show that this is not the case in a natural state. The date of emergence from the pupa is usually two or three days earlier in the male than the female, and the proportion of males not much greater than of females. But in a wild state the proportion of males of both P. apollo and P. delius always seems to be much greater; and from the comparative rarity of the females in almost all the species of the P. apollo group this seems to be the case in other countries. But in the P. mnemosyne and P. delphius groups females, though occurring somewhat later, seem usually to be nearly as abundant as males. Notes on the Copulation of Parnassius apollo. By ARTHUR THOMSON. " On the 18th of June, 1885, I received forty pupse of Parnassius apollo, which had been sent to the Gardens by order of Mr. H. J. Elvves, F.Z.S., for the purpose of watching the perfect insects when copulating, and to endeavour, as far as possible, to throw some light upon the development of the 'horny pouch' with which the female is provided after copulation. " H o w far I have been successful I must leave others to judge, but 1 wish to say that the fact of the female Parnassius developing such a 'pouch' after emerging from the chrysalis was quite new to me, so that I had no preconceived ideas upon the subject, and I have noted the facts just as they occurred. " I first had a large gauze cage made, and placed in it six plants of Sedum telephium, the food of this species, and put in the insects as soon as they were ready, after emerging from the pupae. " The first and second copulations took place on June 27; the first pairing lasted from 1 1.10 A.M. to 2.25 P.M. = 3 hours 15 minutes, and the second pairing lasted from 11.30 A.M. to 3.0 P.M.=3 hours 30 minutes. The ' pouches' in each case were perfectly developed, and the females began to deposit their eggs upon the gauze within five minutes of their separation from the males. |
