208 
THE ART OF REARING 
is tedious and unnecessary *. The chrysalis always 
exists in the cocoon, and is sure to be healthy, if 
the laboratories have been well managed. 
It will happen sometimes that the silk-worms 
in forming the cocoon, when drawing the last por- 
tion of the silk, cannot carry the floss quite per- 
fectly from one extremity to the other, or do not 
fasten it well to the inside ; notwithstanding this, 
which prevents the extremities being well covered 
with silk, and causes the threads to cross the co- 
coon irregularly, the chrysalis will be found to be 
perfect and healthy. 
In such instances, on shaking the cocoon, it may 
very probably not rattle, being fixed by the 
threads, although it be perfectly sound. How- 
ever, such as are inclined to make these trials 
may do so ; I have stated my opinion of their 
inutility. 
There are no certain signs to distinguish the 
* The following' observation is from L’Abbe Rozier's 
work: “ When choosing the cocoons for the production of 
the moths by shaking the cocoon close to the ear, may be 
ascertained whether the chrysalis be alive. If it is dead, 
and loosened from the cocoon, it yields a sharp sound. The 
muscardin, or cocon drag&e *, produces the same sound. 
But when the chrysalis is alive, it yields a dumb muffled 
sound, and is more confined in the cocoon . — ( French Trans - 
lator.) 
a There are no corresponding terms in English for the 
various diseases of Silk-worms, and it has been thought best 
to retain the original Italian or French term . — (English 
Translator.) 
