132 CRABS AND INSECTS. 
white cocoon. They now change to a chrysalis, and in 
eight or nine months escape, a perfect insect. A South 
American member of this family has a swinging, basket- 
like cocoon (Fig. 167). 
Fic, 166,—The silk-worm, moth, and cocoon, on a mulberry branch, With 
view of silk works, illustrating the economic value of the worm. 
