1886. ] MR. H. J. ELWES ON THE GENUS PARNASSIUS. 9 
and P. mnemosyne dissolved when boiled in the same chemical, 
leaving only brown oily drops. The alkali was then saturated 
with mineral acid, but nothing organie was separated from it, 
whence we must conclude that the originally dissolved substance 
was destroyed. 
Siebold compares the pouch of P. hardwicket, which he saw in 
the Vienna collection, with that of P. mnemosyne, from which, how- 
ever, as I have afterwards shown, it is very different. He also 
compares the pouch of P. delins with that of P. apollo, and says that 
it agrees in colour, texture, and shape, wanting only the sharp keel. 
In this, however, he was mistaken, as I have never seen a specimen 
of P. delius, or of any species of this group, in which the keel was 
absent, though in P. jacquemonti, which Siebold could hardly have 
seen, it is so. 
He then describes the observations of Herr Reutti, of Freiburg, 
who undertook the rearing of P. apollo from the larva in order to 
prove the correctness of Siebold’s views. On May 29 he collected 
fifty larvee, which had mostly undergone their last moult, on Sedum 
album. He describes them as being very troublesome to rear, 
because the larvee, though feeding greedily when placed on the 
plants, would not return to the food of their own will, owing to the 
want of sunshine in a room of north aspect. 
He succeeded, however, in rearing 11 larvae, which went into pupee 
under plants or stones, and in one case in an angle of the cover of 
the cage in a slight web of spun threads; “within this the larva 
hung by the hind feet in the manner of a Vanessa; the pupa, how- 
ever, lay free in the web.” Reutti succeeded in rearing four pairs 
of the butterfly, one of which, on July 17 at 1 p.m, united, and 
remained in coitu until late at night; next morning they were 
separate, and the female had a perfect pouch; but no observation 
was made of its formation. 
Siebold thinks that the keel in the pouch of P. apoélo is produced 
as follows: “ By observing the male genital organs of P. apollo, it 
seems to me that the coagulating secretion is poured out under the 
two lateral valves, which, on the end of the abdomen of the male 
beneath, keep the proper genitals embraced, so that these latter, 
after coagulation of the pouch-forming secretion, are found in the 
interior of the pouch, whilst the valves are pressed against the out- 
side of the vault of the pouch, and part of the coagulated matter 
stands out between them as the above-mentioned keel.” 
Lastly, Siebold quotes Kollar for an extraordinary story about 
the larve of P. mnemosyne, which are preserved in the Imperial 
Collection at Vienna, resembling those of P. apollo in habit, colours, 
markings, and which are ‘not seldom found on recently dead horses 
in the lower mountain valleys of Austria and Hungary”’!!! 
On the same evening that this paper was read, I had hoped that 
Prof. Howes would have been able to give us the result of his exami- 
nation of the specimens preserved at the Society’s Gardens as here- 
after mentioned ; but Prof. Howes having been delayed by illuess and 
press of other work, his observations will form the subject of a later 
