332 
ON THE PRODUCTION OF 
supply of moths of equal strength. It is for this 
reason that I advise the setting apart in the third age 
of 300, although 1 70 cocoons reared in this manner 
generally produce an ounce of grain. 
Every year fifty cocoons must be left, twenty-five 
in each of the two manchons, from which will be 
hatched the moths that are to lay the grain on the 
mulberry tree. If the tree is too bushy, it is better to 
•cut off some branches, so as to facilitate the coupling 
of the moths. 
This grain will pass the winter on the tree, and will 
Ibe hatched naturally in the spring ; this is the store 
from which the worms are produced to be reared on 
the tree the following year. I propose two manchons, 
as a double provision to guard against accidents during 
the long lapse of time through the winter. It must 
"be well understood that I speak here of the education 
needed to obtain one ounce only of grain ; whoever 
wishes to obtain more will naturally have to make a 
greater proportional provision. 
By the education on the mulberry tree every race of 
silkworm may be regenerated in a short time. At 
the end of three years of successive education and 
hybernation on the tree, the blood of the larva, under 
microscopic examination, becomes exactly like that of 
the wild bombyx. With a little practice this work is 
easily accomplished ; the necessary materials are as we 
have seen, very simple, and may last many years. 
Thirty mulberry trees, cut as explained above, and 
ten manchons, suffice to rear the silkworms which 
ought to produce an ounce of grain. 
The period of education, from the time of hatching 
to that of forming the cocoon, necessarily varies, 
