Silkworm from Japan. 369 
March 19th, 1866. I received by post from Mons. Personnat, 
of Laval, France, a letter, outside which was fastened a_pill-box, 
perforated with a few holes; within the box, which fortunately had 
not been crushed tn transitu, were some Yamamai eggs; on 
examination 147 appeared to be sound and plump, covered with a 
rusty brown gum; one, which appeared plump (and which after- 
wards hatched out a larva), was of a straw-coloured white, it was 
not depressed in the centre, but simply devoid of gum; twenty other 
eggs were much depressed in the centre, and two were pierced ; 
one egg was cracked, and contained on examination a fully-formed 
dead larva; three more were doubtful, being flattened, but in a 
less degree than the others: total 174. Their diameter was 51, 
inch; thickness ,!; inch. The eggs, I remarked, much resembled 
those of B, Pernyi, another oak-feeder from North China, which 
had been sent to me ina former year by Mons. Guérin- Méneville. 
In his note, Mons. Personnat advised me to keep them in a cool 
airy place. On opening one of the eggs which were depressed in 
the centre, for the purpose of examination, a yellowish dry serum 
was contained within, caked; but there was no trace of a worm; 
these then evidently were non-fertile eggs. The interior aspect of 
the shell of the cracked egg, whence a dead larva was taken, was 
polished and ofa pale flesh colour, J placed the 148 sound eggs 
in one pill-box and the doubtful eggs in another pill-box, having 
made holes for aération with a penknife in both the lid and bottom 
of each box ; these boxes were placed within a second larger tin 
box, which was used for collecting larvae and which had perforated 
sides for aération; a little tow was placed therein to steady the 
smaller boxes and the whole placed in a cellar, where by means of a 
thermometer the temperature was found to stand at 50° F.; on the 
20th, not being satisfied with the temperature of the cellar, fearing 
that it was too high, I divided the sound eggs into two portions, 
one of eighty-eight, the other of sixty, and placed them in fresh 
pill-boxes as before and afterwards in two tin boxes, which were 
both similarly made ; the smaller lot I placed in a porch having an 
eastern aspect, where it was completely shaded from the sun’s rays, 
and where the thermometer stood at 46°; with this box was also 
placed the box containing the doubtful eggs, which, however, I 
may as well at this point mention never produced a larva; the 
other larger portion of sound eggs I placed in the N.E. corner of 
my garden, under a wall where the sun’s rays could not penetrate. 
The same situations were occupied by the eggs up to the 27th, on 
which date I placed the second lot in the porch. I subjoin a list 
