SILK-WORMS. 
327 
Its length, from the period of the largest growth 
until it changes into the chrysalis, diminishes about 
two-fifths. 
During and immediately after coupling, the 
moth appears to augment in weight; 100 moths, 
which before coupling weighed 2990 grains, weigh 
immediately after 3200 grains. This is caused by 
the weight of the matter injected by the male, 
which is heavier than all the female had lost at 
the same time. 
The worm diminishes gradually in weight 
during the last twenty-eight days of its existence ; 
that is, from the moment of attaining its perfec- 
tion as a worm, until its death in the form of a 
moth, it eats nothing, is supported by its own 
substance, and yet accomplishes in that period the 
most important functions of its life. 
The facts I have stated demonstrate the strong 
vitality of the silk-worm, and what pains and er- 
rors must be adopted to disease and kill it. 
5. Facts relative to the Cocoons containing the 
healthy Chrysalis, the diseased Chrysalis, and 
the dead Chrysalis. 
When the cocoons are perfectly formed, they di- 
minish, in the four first days, three-quarters per 
cent, each day ; the other days the diminution is 
very trifling. 
