384 Dr. Wallace on the Ouk-feeding 
this morning; he was placed along with others on a tree in the 
greenhouse, after hydropulting ;* changed the oak sprays upstairs. 
It now seemed to me that some of my larve in the greenhouse 
were gone, and in consequence I watched more closely, and soon 
found a larva attacked by a spider, which I killed in the act; the 
larva was wrapped up in a shroud of silken thread, which I could 
not detach ; it seemed paralyzed and torpid. On further examina- 
tion it was found to have been bitten near the head ;_ it remained 
torpid, discoloured, and evidently dying for twenty-four hours, 
when it was put into spirit. It was now quite clear how my 
Jarve in the greenhouse had gone. The Jarve on white-thorn had 
not fed, and were therefore transferred to oak. The leaves of the 
tree upstairs, and which had been first fed upon, were dry, hard 
and crisp, and the edges which had been nibbled were black and 
studded with a thin film of mould; some of the larve thereon 
seemed shrunken and discoloured, but the larvee in the greenhouse 
were thriving. There were therefore difficulties both upstairs and 
in the greenhouse to overcome, and I removed one of the two oak 
trees and two trays of oak sprays into the greenhouse, the tem- 
perature during the night of the 17th—1I8th being 47° in the green- 
house, at 9 a.m. 65°; upstairs, minimum temperature during 
night 54°, in shade 58°, in sunshine 80°; at 8 a.m. several larvee 
were found shrivelled on the oak trees, evidently from the food 
being too dry, and containing no suitable nourishment. 
May 18th. The temperature in the greenhouse to-day being 
high, many of the larvee were found wandering away from the 
food, to get into the shade as it were. I removed therefore the 
two trays upstairs, and the larvae soon settled down again on the 
leaves to feed; the larva which had moulted for the first time fed 
during the night. I took a fresh oak tree upstairs and brought 
back several larve from the greenhouse, where the thermometer 
stood at 65°—70°. I examined five eggs of No. 4 lot, by cutting 
a bit of the shell out with a sharp knife. No. 1 contained a larva, 
dead; No. 2, an aggregation of molecular granules, yellow and 
soft, but no form of a larva; No. 3, a yellow molecular mass more 
organized than No. 2, having a curled-up form, with a central 
depression ; No. 4, a transparent solid yellow serum with a white 
patch; these four eggs were very mouldy outside; No. 5 was not 
mouldy, but had a plump, healthy look; it contained a larva inside, 
well developed, but devoid of movement, dead. Of these five 
* The larve bear a sharp stream of water directed on them with impunity; 
they naturally cling tight, and, being on the under surface of the leaf, are 
protected from the violence of the shower, 
