370 THE LOCUST 



surface. Plowing a field destroys most of the grasshoppers, 

 because the surface is turned under so deeply that the eggs are 

 destroyed or the young cannot escape after hatching. The period 

 of development within the egg membrane is termed the embryonic 

 period. At the time of hatching (cf. Figs. 187 and 188), the 

 young locust resembles the adult, although the head is relatively 

 larger and the wings have not yet appeared. The individual 

 develops by a series of molts until it reaches adult proportions. 

 Such a mode of development may be termed direct, since there 

 are no larval stages markedly different from the adult which 

 must change or metamorphose to reach the final condition. In 

 contrast with this, the development of the frog, with its tadpole 

 stage (Fig. 11, p. 23), or that of the butterfly, with its caterpillar 

 stage (Fig. 195, p. 380), is termed indirect development, or meta- 

 morphosis. The grasshopper is sometimes referred to as an insect 

 with incomplete metamorphosis, but this is no more justifiable 

 than to say a chick develops by incomplete metamorphosis, 

 because at birth it is not exactly Hke the parents. It is true, 

 however, that, taking the insects as a whole, one finds all gradations 

 between direct development, Hke that of the locusts, and a most 

 complete metamorphosis, such as is shown by the moths and 

 butterflies. 



