148 THE AMERICAN SILK WORM. 
were made perfectly air-tight. They were kept in a cold 
dry room all winter. In July the moths came out per- 
fectly healthy, the fluid they discharge through the mouth 
having perfectly dissolved the starch and varnish. So 
these insects had been nine months with no air, except the 
very small volume enclosed in the cocoon, and they had 
accomplished their transformation just as well as if the 
air had been allowed to come into the cocoon. 
: It seems to me that when once enclosed in the cocoon, 
the pupa is in a transitory state. The process of assim- 
ilation, at least during the cold days, seems to have 
ceased. In the stomach of chrysalids can be found an 
albuminous, greenish substance; probably it is a food 
which can be assimilated, or at least transformed into 
some of the liquids which are discharged by the perfect 
insect when coming out of, the cocoon. If there is any 
elaboration of the food in the chrysalis, the process must 
be very slow, and surely no air is needed to accomplish 
it, nor any food, except what little food is in the stomach. 
The most striking phenomena manifested by life is the 
assimilation and elimination of food; but to assimilate, 
the animal must take food, either in the solid or gaseous 
form. We know that the chrysalis cannot eat; breathing 
-is very problematical. Before changing into a chrysalis, 
the worm evacuates all the contents of its stomach; 
so, in my opinion, the chrysalis does not breathe, or if at 
all, it is so very slight as to be insignificant. 
There is not much possibility ur being able to obtain 
two broods of the Silk Worm in the same year in this 
latit ude. > earliest date at which I have obtained co- 
coons was he first of August, twenty-two days after the 
moth hatched from the cocoon. On the fifth of Septem- 
ide ceo peo age 
