210 
THE ART OF REARING 
duce good eggs ; in a hundred, there will scarcely 
be one that will fail in producing a strong sound 
moth. 
We must also add, that as to the means of dis- 
tinguishing the sexes of the moths, though there 
may be signs that give general indications of the 
difference, yet they are not so infallible as not 
sometimes to mislead us. 
3. Preservation of the Cocoon intended for Seed. 
The preservation of the cocoons destined to pro- 
duce eggs, is an operation of some importance. 
It will require a very dry room, exposed to a 
temperature of between 66° and 73°. 
Experience shews us, that were the temperature 
above 73°, the transition of the chrysalis to the 
moth state would be too rapid, and the coupling 
will not be so productive. If the temperature is 
below 66°, the development of the moth is tardy, 
which is also injurious, as we shall shew hereafter. 
If the apartment is not dry, the damp, which was 
hurtful to the worms, will be equally so to the 
chrysalis, and change it into a weak and sickly 
moth. The apartment should be kept in an even 
temperature, between 66° and 73°, and the rooms 
on the first floor should be preferred to a ground- 
floor apartment. 
As soon as the cocoons are collected which are 
intended to produce eggs, and are spread either on 
a dry floor or on tables ; an active hand should 
