50 
SECOND BOOK. 
Often it first spins for itself a cocoon or covering, in 
which it passes through its second stage of life, called 
the chrysalis. During that stage a great change is 
steadily going on, and at last from the dry, dead- 
looking chrysalis, the perfect insect bursts forth.” 
Metamorphoses of Butterfly. 
a, The eggs ; b, caterpillar ; c, chrysalis ; d, the perfect insect. 
3. The boys thought it very wonderful that one 
creature should have so many different shapes in its 
lifetime, and William said that it reminded him of 
the tadpole changing into a frog. 
4 . “ No doubt insects are of some use in the 
world,” said William, “ but many of them are very 
troublesome sometimes, and a nuisance to us. They 
often destroy the wood of our trees, furniture, and 
