12 MR. H. J. ELWES ON THE GENUS PARNAssIvs. (Jan. 19, 
torpid without flying; that the duration of the act is from 33 
to 63 hours, but the pouch is developed in a much shorter time, 
thirty minutes in one ease sufficing to make it visible to the naked 
eye. But my observations of P. mnemosyne makeit 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 
pouchless 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 
already mated female, but my 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 compara- 
tive 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 Artuur THomson. 
“On the 18th of June, 1885, I received forty pupz of Parnassius 
apollo, which had been sent to the Gardens by order of Mr. H. J. 
Elwes, 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. 
‘«* How far I have been successful I must leave others to judge, but 
I 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. 
“{ 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 pupe. 
“The first and second copulations took place on June 27; the 
first pairing lasted from 11.10 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. 
