Silkworm from Japan. 413 
the acorns are on long stalks. Q. sessiliflora, or sessile-cupped 
oak, is distinguished by having its leaves on long stalks, and its 
acorns on short stalks, or else sessile. This tree is preferred, 
though a little later in breaking, for the culture of the Yamamai, 
on account of the greater length of its stalk permitting a freer 
ventilation of air, and a better observance of the larva. Q. pubes- 
cens, distinguished by the woolly character of the leaves on the 
under side, otherwise resembling sessiliflora, and Q, cerris, the 
Turkey oak, and Q. Agilops, the great prickly-cupped oak, are 
all equally well eaten by the Yamamai. It is desirable to keep 
the worm on the leaves of the same tree during the first stage. 
The commencement of the first moult is known not only by the 
worm seeming dull and refusing to eat, but also by the appearance 
of a sort of triangle at the head, formed by the new head growing 
too large for the old one, and pushing it forwards. Great stress 
is laid by the French writers on the worms all being of the same 
age, in order that all may go through their moultings simultane- 
ously, for fear lest while they are moulting, and the branches are 
undisturbed, younger larvee might starve from want of food ; and I 
suppose this is true when large numbers of larve are reared ; but 
I have, during the moulting, changed the food regularly, cutting 
off with scissars the portions of spray or leaflets whereon the larva 
was attached for moulting, and placed it on the wooden tray, in a 
horizontal position, without any detriment to the larva. 
After every moult the epidermis is very tender for several 
hours, and great care must be taken not to injure it in changing 
the food, &c.; in like manner also, as the jaws are soft, it is 
desirable that the food supplied should be very tender. By the 
beginning of May the worms will be in their second or third stage, 
and may be left out of doors during the night. In this way they 
-will be naturally moistened with the dew, of which they are very 
fond. 
If itis wished to place the crop on oak trees in the open air, the 
most suitable time will be in the middle of the second or third 
stage, the latter perhaps the best in point of time, about the 
10th of May, a period at which, in our gardens, the geraniums are 
placed out, the same weather being equally suited to that plant 
and the worms. ‘Trees that have been pollarded or stooled to a 
height convenient for guarding and observing the larve should be 
selected, having shoots two or three years old, those of one year 
being rather too soft and watery. All spiders and other injurious 
vermin should be dislodged. The trees should, for this purpose, 
