1886.] MR. H. J. ELWES ON THE GENUS PARNASSIUS. 1) 



and p. mnemosyne dissolved wheu boiled in the same chemical, 

 leaving only brown oily drops. The alkali was then saturated 

 with mineral acid, but nothing organic was separated from it, 

 whence we must conclude that the originally dissolved substance 

 was destroyed. 



Siebold compares the pouch of P. hardwickei, 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. delius 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. jacqvemonti, 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 larvae, which had mostly undergone their last moult, on Sedum 

 album. He describes them as being very troublesome to rear, 

 because the larvae, 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 1 1 larvse, which went into pupae 

 under plants or stones, and in one case in an angle of the cover of 

 the cage iu 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 coitii until late at night ; next naorning 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. apollo 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 larvae 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 ilhiess and 

 press of other work, his observations will form the subject of a later 



