242 NATURAL HISTORY. 



on the leaves of trees till August or September, and then 

 descends to seek for some currant or barberry bush upon 

 which it may build its house for its winter sleep. " Any 

 one," says Professor Jaeger, " who meets with these 

 caterpillars in the above-mentioned months may have 

 the pleasure of witnessing their metamorphosis into co- 

 coons, and several months after into an elegant moth, by 

 taking them up very carefully upon leaves and carrying 

 them home, placing them in a spacious box, with a little 

 undisturbed earth at the bottom, and then putting into 

 it some dry brush-wood, about one foot high, and cover- 

 ing the whole with gauze in order to prevent their es- 

 cape." 



415. I will now describe the peculiar construction of 

 the cocoon. That of the Silkworm is a simple cocoon, 

 no special provision being made against the cold, as the 

 pupa state, instead of lasting through the whiter months, 

 is finished in a few weeks. But in the case of the Ce- 

 cropia Moth there is a covering outside of the proper 

 cocoon. This covering is fastened to a branch of some 

 bush, as in Fig. 188. It is made very strong, as its fibres 



Fig. 188. 



are much more closely joined together than those of the 

 cocoon inside of it. Often there are leaves attached to 

 it, leaving the impression of their veins or nerves upon 

 it when you have detached them. The animal evidently 

 uses these leaves as a sort of scaffolding when it begins 

 to construct its winter home. In spinning this covering 

 it works all the while inside, as it does in spinning the 

 cocoon. After finishing it, it lines it with coarse loose 



