168 THE ENTOMOLOGIST. 
FURTHER NOTES ON CERTAIN SILK-PRODUCING 
BOMBYCKS. ~ 
By Atrrep WAILLY. 
As my notes on “Silk-producing Bombyces” (published in 
the ‘ Entomologist’ for December, 1878, and January, 1879) were 
written very hastily through want of time, I beg of you to add 
the following remarks on the subject. 
On page 264, fifth line, respecting the length of branches 
used for feeding the larve, the word yards should have been put 
instead of feet. 
IT now come to a most important point—the reproduction of 
the species in a state of confinement. From a perusal of my 
notes it will be seen that two species—Attacus Pernyt and Samia 
Cynthia—pair very readily; but with most other species pairing 
is the exception rather than the rule. Why should Pernyi and 
Cynthia pair very readily in any situation, and most other species 
only accidentally? In a state of nature certain species are 
reproduced to a far greater extent than others. When in a state 
of confinement the moths of exotic or even native species suffer 
from several causes—want of room, air, moisture, &c. With 
respect to native species, the cages containing the moths may be 
placed in the open air, and moisture may be supplied by watering 
the cages or placing wet sponges in them; but exotic species, if 
treated in the same manner, may have to suffer from another 
cause—the climatic difference between their native country and 
that of England, or any other northern country. 
Hence the difficulty of obtaining fertile eges, especially of 
exotic species, even supposing that male and female moths 
emerge simultaneously, which is not often the case unless a large 
number of pup be kept. In the middle of July I had at one 
time twelve fresh Atlas moths, male and female, three of which 
were of the giant race, yet I could not obtain a single pairing. 
Previously I had obtained a pairing with two of the smaller 
species of Atlas. With about fifty cocoons of Pyri, I only 
obtained three or four pairings. 
Some persons think that if they have a few pup of one 
species they are certain to obtain fertile eggs. This is a great 
mistake, although the thing is not impossible. Now with - 
