€H. XIII.] HISTORY OF THE CICADA. 201 



which, in some respects, agrees with the one just 

 described. During the mid-day heat, a copious and 

 refreshing supply of limpid dew, or rather rain, may 

 be seen to fall from the branches of the trees, which 

 is caused by the larvas of Cicada {Aphrophora) 

 Goudoti. The larvas are found in clusters, envel- 

 oped by a whitish froth very similar to the cuckoo 

 spit. They are in constant agitation, and pressing 

 eagerly upon each other in their attempts to apply 

 themselves to the surface of the bark, from which 

 they extract the sap in such quantity as to maintain 

 their bodies in a state of saturated humidity. This 

 sap is afterward discharged, and forms drops of 

 small size, which are gradually collected into larger 

 drops, and appears to escape from the bodies of the 

 larvae with a rapidity proportioned to the action of 

 the solar rays. The activity of the larvae is, in fact, 

 increased in a corresponding degree with the in- 

 crease in the atmospheric temperature. Towards 

 evening, and when the influence of the solar rays 

 is sensibly diminished, the production of the fluid, 

 thus singularly secreted, is partially suspended, and 

 the drops fall slowly ; as the night advances a few 

 rare and tardy drops are heard at distant intervals, 

 until at last they altogether cease, to be renewed 

 with the first rays of the morning sun. When fifty 

 or a hundred such clusters of larvae are placed, as 

 often happens, on the same tree, it may well be 

 imagined that the secretion may become sufficiently 

 copious to assume the appearance of actual rain. 

 In a mass of sixty or seventy individuals, about 

 half grown, the sun being powerful, the drops were 

 very large, and fell in quick succession. The ob- 

 server estimated, that setting aside the loss by evap- 

 oration, and by the animals. which drank from the 

 vessel, he could have filled a bottle, containing 

 about a quart, in an hour and a half. The limpid 

 character of the water encouraging the belief that 

 it was free from any pernicious qualities, he tasted 



