396 Dr. Wallace on the Ouk-feeding 
separate and proved to be quite fertile. ‘The males were more nu- 
merous at the commencement, the females towards the close of the 
period of emergence from the cocoon. A great many fully fertile 
egos were obtained. 
In page 115 of the Revue de Sériciculture of 1864 is an account 
by Mons. Bonnard, of Marseilles, of his experience, in a letter to 
Mons. Guérin-M éneville :—“ I received a box of eggs (160) from 
you the 20th February; the eggs were at once placed in a room 
with a north aspect, but notwithstanding my precautions, on the 
22nd a worm hatched out to my surprise and despair. I had then, 
alas, no oak trees sufficiently advanced. This worm died, though I 
gave him leaves of the evergreen oak. On the 24th another, on the 
26th four more, on the 28th thirteen, on the 29th eleven, and others 
came out successively up to the 8th March. All except the last 
few died of hunger. I had, moreover, 175 eggs laid by a female 
Yamamai the preceding year ; none of them had yet emerged and 
I hoped they would not hatch till the leaves were ready; but 
on the 4th March they began, and continued to emerge till the 
15th. Inthe meantime the Zoological Society of Acclimatization 
sent me on the 11th a gramme of eggs; some had hatched when 
they arrived, others hatched the next morning, &c., but two- 
thirds of the eggs were dried up. During the first few days of 
March, my wife and I offered leaves of various kinds to the young 
worms; they ate willingly the Neapolitan medlar, as also the 
hawthorn, but refused the quince. Hence I hoped to preserve the 
stock. During the first moult many died, and on the 26th I had but 
80 out of about 300 hatched out. I travelled with these to the 
Basses Alpes; on the 3rd April I arrived at Marseilles. There, 
oaks forced under glass supplied them with natural food till the 
7th, on which day, in a warm spot, [ found a young oak breaking 
into leaf. During the night the worms were in a room, during 
the day they were constantly out of doors in the shade. About 
the 12th, though they had been watered daily twice or thrice, a 
kind of epidemic (gattine) appeared. I thought this was the result 
rather of my keeping them indoors at night than of the change 
in their diet ; whatever the cause, the feet became black, then the 
whole body, and nothing seemed to stay the malady. On the 
15th but forty worms more or less stricken remained. J then 
took each worm, dipped him in water for several seconds, replaced 
him in fresh well-watered foliage, and left the worm out all night 
long. After two or three dippings all trace of discase disap- 
peared ; and I have now thirty-four magnificent caterpillars in 
