Silkworm from Japan. 397 
robust health, nearly ready to spin their cocoons ; the leaves are 
changed twice a week ; they are watered twice or thrice daily, and 
are constantly out of doors. I am confident that the evening dew 
is beneficial to them, and that these cocoons might be cultivated 
in a little oak plantation, taking care to keep away birds, and 
water them artificially. Next year I propose, in order to keep 
my eggs better, to place them in a room where the temperature 
never falls below freezing point, and take them about the begin- 
ning of February to an uninhabited apartment among the oak 
trees.” 
M. Oscar Zlik, of Teschen in Silesia,* writes, having received 
fifty eggs from Mons. Guérin-Méneville, “The young worms 
began to hatch out the 11th April, but I had no oak leaves for 
them. In vain did I try to retard them; only the last three, 
which were born the 27th April and the 2nd and 3rd May, could IL 
save; they eat the leaves of Quercus pedunculata and sessiliflora: 
the first stage lasted 8--10 days; the second, 7—8 days; the third, 
7 days; the fourth, 10—12 days; the fifth, 17—18 days; in all, from 
52—54 days. The first worm, born 27th April, began to spin 
June 19; the second, born 2nd May, on June 22; the third, born 
8rd May, on June 26.” 
Mons. Frerot, of Aussonce, writes,| ‘‘ Out of 133 eggs received 
fifty were dried, out of the remaining eighty-three but sixty-two 
hatched; eleven worms died soon after birth, another was acci- 
‘dentally drowned ; twenty-five are now, while I -write, spinning, 
and in a few days I bope other twenty-five will spin; each worm 
spins regularly fifty days after hatching; from twenty-five cocoons 
kept by me, ten males and twelve females emerged, three did not 
emerge. I only got six fertile pairs, and about 1,500 good eggs. 
Coition, to my surprise, lasts a very short time; I had to visit my 
moths at various times in the night to satisfy myself as to the point. 
I have placed the eggs in bottles, well corked and sealed, in a 
cellar; when the temperature of the room is lower than in the 
cellar, | shall withdraw them, and replace them in the cellar in 
spring. It was thus that I treated the eggs which I received last 
February. Out of each batch of new eggs I took five or six and 
exposed them to such a temperature as would ensure incubation ; 
on opening these I found in each a worm fully formed.” 
The first experiments, therefore, in France, though on the whole 
* Revue de Sériciculture, 1863, p. 325. 
t Ib. p. 326. 
