CH. XIII.] HISTORY OF THE CICADA. 191 



tion of the term, and call those sounds vocal by 

 which animals determine others of their own species 

 to perform certain actions, then insects may be said 

 to have vocal organs; and those of the cicadae 

 amply merit our attention. 



On the under surface of the male insect, two semi- 

 circular pieces, of a horny substance, are placed, as 

 represented in the lower figure by the letter u. If 

 these be lifted up, we cannot fail being struck with 

 the complicated apparatus which is now exposed to 

 view. The same care, the same excellence of work- 

 manship, is displayed in contributing to the wants 

 of these insects, as in those of man ; and the organs 

 by which the cicada calls its male will bear a com- 

 parison with the larynx of higher animals. 



The two horny lids, u, conceal a cavity in the ab- 

 domen of the insect. This cavity is divided into 

 two by means of a triangular partition. Each of 



the two cells or cavities appears to be lined with a 

 looking-glass, m ; and children, who amuse them- 

 selves by catching these insects, are pleased with 

 the rainbow teints which they see when the light 

 falls obliquely on these lustrous membranes. Such 

 is their transparency, that the cicada appears to have 

 two windows, through which the curious eye is per- 

 mitted to look into the interior of its mysterious 



