OP THE FARM AND GARDEH. 195 



the earth they seem to follow the roots of plants, and are 

 subsequently found attached to those which are most 

 tender and succulent, perforating them with their beaks, 

 and thus imbibing the vegetable juices which constitute 

 their sole nourishment. 



The grubs do not appear ordinarily to descend very 

 deeply into the ground, but remain where roots are most 

 abundant. The only alteration to which the insects are 

 subject, during the long period of their subterranean con- 

 finement, is an increase in size, and the more complete 

 development of the four small scale-like prominences on 

 their backs, which represent and actually contain their 

 future wings. Fig. 118, a, represents the full-grown 

 larva. 



When at length the time arrives for them to issue from 

 the ground they come out in great numbers in the night, 

 crawl up the trunks of trees, or upon any other object 

 in their vicinity to which they can fasten themselves se- 

 curely by their claws. After having rested awhile, they 

 prepare to cast off their skins, which, in the mean time, 

 have become dry and of an amber color. By repeated 

 exertions, a longitudinal rent is made in the skin of the 

 back, and through this the included Cicada pushes its 

 head and body, and withdraws its wings and limbs from 

 their separate cases, and, crawling to a little distance, it 

 leaves its empty pupa-skin, apparently entire, still fas- 

 tened to the tree as in fig. 118, #. At first the wing-covers 

 are very small and opaque, but, being perfectly soft and 

 flexible, they soon stretch out to their full dimensions, 

 and in the course of a few hours the superfluous mois- 

 ture of the body evaporates, and the insect becomes 

 strong enough to fly. 



During several successive nights the pupae continue to 

 issue from the earth; above fifteen hundred have been 

 found to rise beneath a single apple tree, and in some 

 places the whole surface of the soil, by their successive 



