34 



INSECT LIFE. 



plete a series as possible representing the changes 

 from the very young insect without any wings, 

 through the different stages of wing-growth up to 

 the adult insect. 



The accompanying figures (Figs. 1 1-16) represent 

 the transformations of a common locust. Note that 



Fig. is.— Nymph of Melanoplus, FiG. %t.—Melanoplus, adult, 



fifth stage. (After Emerton.) 



the figures of the younger stages are enlarged. The 

 hair line represents in each case the length of the 

 insect. 



LESSON XIII. 



INCOMPLETE METAMORPHOSIS. 



Nearly all insects undergo great changes in form 

 while getting their growth. Thus, caterpillars in 

 time become butterflies or millers; grubs when 

 fully developed are beetles; and maggots are the 

 young of two-winged flies. 



In the case of butterflies, • millers, beetles, and 

 t^o-winged flies, the fully developed insects bear 

 but little resemblance in form to the young. It 

 would be difficult to find two adult insects that differ 

 more in form than do a butterfly and the caterpillar 

 from which it was developed. But in the case of 

 certain other insects, the changes undergone during 

 the life of the insect are not nearly so great as with 



