1886.] MR. H.J. ELWES ON THE GENUS PARNASSIUS. 45 
As far as I have personally observed, it is found in meadows where 
vegetation is rather rank ; and at Berisal, on the Simplon pass, where 
it is most abundant at 4500 feet, the meadows where it flies have a 
north aspect, while P. apollo confines itself to the hot slopes on the 
other side of the ravine. ' 
With regard to its life-history little is known. Meyer-Dir says 
that Kindermann discovered the apollo-like larva in April and 
beginning of May on Corydalis halleri, and that it pupates under 
fallen leaves in a strong web, the pupa being yellowish and like that 
of the Zygenidee. I have made several endeavours to discover the 
larva myself without success, but I have strong doubts that Corydalis 
is the only, if even it is the usual food-plant, for this reason, that it 
is a spring flowering plant of very short duration ; whilst P. mnemo- 
syne must be an autumn-feeding larva, as the insect flies in spring 
or early summer very soon after the melting of the snow, and there 
could be no time for the larvee to feed up after it melted. 
From observations made in Wallis, in June 1884, and again in 
May 1885, I believe that the larva more probably feeds on an um- 
belliferous plant (? Heracleum, sp.), which was very abundant in the 
places where the insect was numerous, and on which the females 
often sat, whilst Corydalis was either absent or withered at the 
same date. Herr Bang-Haas thinks that in Dénmark the larva is 
a night-feeder, but knows nothing certainly about it. I was very 
anxious to investigate the development of the pouch in this species as 
well as in P. apollo, and with this object visited Wallis in May 1885. 
On May 24, 1 found the males abundant at about 3000 feet on the 
south side of the valley, near Brieg, and caught several males and 
fresh females, all of which had the pouch perfect. In the previous 
year I found, a month later, at Berisal, that the males were worn, 
and the females, though they were in two or three cases taken in 
copula, had apparently been flying for some time, and had a perfect 
pouch. After a good deal of searching I found a female fresh from 
the pupa, at about 11 A.M., sitting on an umbelliferous plant, either 
Aithusa or Heracleum. took her home and put her in a birdcage 
covered with gauze at about 2 p.m., and at 2.30 one of the males 
which had been fluttering round her for some time commenced 
copulation. The female held on to a grass stem with the head up- 
wards and the male hung to her with head down. At 2.45 the female 
crawled up to the top of the cage, carrying the male with her; he made 
no attempts to use his feet or hold on, and was supported entirely 
by the abdomen. At intervals of a few minutes there were slight 
movements of the abdomen of the male, but otherwise he remained 
quite torpid till about 4 p.m., when the pair suddenly separated 
without any appearance of a pouch on the female, whose abdomen 
remained large and swollen as at first. At 6 p.m. there was not 
the least change in her appearance ; she remained quietly holding on 
to the gauze, whilst the male crawled about the cage. In the even- 
ing I put another fresh caught male in, and on the following morn- 
ing put the cage in the hot sunshine at 7.30 a.m. All three insects 
fluttered and crawled about the cage for some time, but showed no 
