Silkworm from Japan. Sie 
elevation of temperature the young larva is tempted to make its 
exit, in order that a due supply of food may be at hand, either by 
forcing the trees and thus obtaining an earlier foliage than can be 
got out of doors, or else by so retarding the eggs in a cool atmo- 
sphere as to prevent the exit till such time as the oak leaves are 
ready: hence the extreme care in noting daily the temperatures. 
I had provided myself with young oak trees four to five feet high 
in pots, which had been placed in a greenhouse to force; on the 
12th of April some of these had shoots six inches long, so that I 
was prepared for the advent of my Yamamai larva, and was 
looking forward with great eagerness to make their acquaintance. 
On the 15th April, I noted in my diary that the oak buds in the 
hedges were swelling; on the 18th, that the buds were breaking, 
so that a week later it seemed as if the time had arrived for the 
larvee and the buds to come out together, according to the accounts 
of the habits of this insect. I had previously, on the 17th, received 
through the kindness of Mons. Guérin-Méneville, eighty-three 
more eggs of the Yamamai. Of these eighty-one were well rounded, 
two were concavely flattened—one to a great extent on both sides 
—the other had a central depression only on one side ; both these 
eges contained, on examination, dried yellow serum—there was 
no trace of a larva. Another egg, which was covered externally 
pretty thickly with long mycelia of a fungus, I took for examina- 
tion; but on chipping off with a sharp knife a small portion of 
the shell, a movement within was visible of a living creature, and I 
therefore proceeded no further. These eggs sent me were plump 
oval ones, slightly flattened on two sides, about one-ninth of an inch 
diameter, one-sixteenth of an inch in thickness; the remaining eighty 
were placed in a pill-box, which was marked and deposited with 
the others in the tin box in the porch. I now inspected the eggs 
obtained from Mons. Personnat, which were in the two tin boxes ; 
they seemed to be healthy; out of each lot I took two for ex- 
amination; in each case one was unfertile, and the other con- 
tained a living larva: I now equalized the numbers, so that seventy- 
six eggs were in each pill-box, and replaced them. I placed 
the three eggs, which I had examined and ascertained to contain 
each a living larva, in a pill-box with a glass lid; and this pill- 
box I placed in the greenhouse, thinking it necessary, now that 
the shell was imperfect and could not so fully protect from cold, 
that the larva should obtain a warmer temperature. On the 25th 
I examined one of these eggs to see how matters progressed: I 
extracted the larva, which seemed torpid, motionless, and as if 
DD2 
