THE PERIODICAL CICADA 



The external phase of transformation, more strictly 

 the shedding of the last nymphal skin, has been many 

 times observed. It is nothing more than what all insects 

 do. But the cicada is notorious because it does the thing 

 in such a spectacular way, almost courting publicity 

 where most insects are shy and retiring. As a conse- 

 quence the cicada is famous; the others are known only 

 to prying entomologists. 



Let us suppose now that our crawling nymph has 

 reached a place that suits it, say on the trunk of a tree, 

 or better still on a piece of branch provided for it and 

 taken into a lighted room where its doings can be more 

 clearly observed. Though the insects choose the evening 

 for emergence, they are not bashful at all about changing 

 their clothes in the glare of artificial light. The progress 

 of this performance is illustrated by Figure 118. The 

 first drawing shows the nymph still creeping upward; 

 but in the next (2) it has come to rest and is cleaning 

 its front feet and claws on the brushes of its face, just 

 as did those confined to the glass tubes to give a demon- 

 stration of their digging methods. The front feet done, 

 the hind ones are next attended to. First one and then 

 the other is slowly flexed and then straightened back- 

 ward (j>) while the foot scrapes over the side of the ab- 

 domen. Several times these acts are repeated calmly 

 and deliberately, for it is an important thing that the 

 claws be well freed from any particles of dry earth that 

 might impair their grip on the support. At last the 

 toilet is completed, though the middle feet are always 

 neglected, and the insect feels about on the twig, grasp- 

 ing now here, now there, till its claws take a firm hold 

 on the bark. At the same time it sways the body gently 

 from side to side as if trying to settle comfortably for the 

 next act. 



Thirty-five minutes may be consumed in the above 

 preliminaries and there is next a ten-minute interval of 

 quietude before the real show begins. Then suddenly 



[195] 



