STRUCTURE AND CLASSIFICATION. 



51 



and one that can be easily accomplished in most cases by any 

 one possessing a little patience. In leaf-feeding insects all that 

 is necessary is to bring in a supply of food with the larva upon 

 it, and keep it in a box or cage, renewing from time to time, so 

 that fresh food may be always available. In the bottom of the 



Fig. 27. 



A breeding-cage of the Riley pattern. 



box there should be three or four inches of clean sand for the 

 benefit of those forms that go underground to change to a pupa, 

 and in due time the caterpillar or slug will, under the observer's 

 very eyes, change to a butterfly, beetle, or other insect, accord- 

 ing to the character of the larva. 



