320 THE DESCENT OF MAN. 



says,* "the drums are now (June 6 and 7, 1851) heard in 

 all directions. This I believe to be the marital summons 

 from the males. Standing in thick chestnut sprouts about 

 as high as my head, where hundreds were around me, I 

 observed the females coming around the drumming males/' 

 He adds, "this season (August, 1868) a dwarf pear-tree in 

 my garden produced about fifty larvae of Cic. pruinosa; and 

 I several times noticed the females to alight near a male 

 while he was uttering his clanging notes." Fritz Muller 

 writes to me from S. Brazil that he has often listened to a 

 musical contest between two or three males of a species 

 with a particularly loud voice, seated at a considerable dis- 

 tance from each other; as soon as one had finished his song 

 another immediately began and then another. As there is 

 so much rivalry between the males, it is probable that the 

 females not only find them by their sounds, but that, like 

 female birds, they are excited or allured by the male with 

 the most attractive voice. 



I have not heard of any well-marked cases of ornamental 

 differences between the sexes of the Homoptera. Mr. 

 Douglas informs me that there are three British species, in 

 which the male is black or marked with black bands, while 

 the females are pale-colored or obscure. 



Orthoptera (Crickets and Grasshoppers). The males in 

 the three saltatorial families in this order are remarkable 

 for their musical powers, namely the Achetidse or crickets, 

 the Locustidse, for which there is no equivalent English 

 name, and the Acridiidae or grasshoppers. The stridula- 

 tion produced by some of the Locustidse is so loud that 

 it can be heard during the night at the distance of a 

 mile;t and that made by certain species is not unmusical 

 even to the human ear, so that the Indians on the Amazons 

 keep them in wicker cages. All observers agree that the 

 sounds serve either to call or excite the mute females. 

 With respect to the migratory locusts of Kussia, Korte has 

 given { an interesting case of selection by the female of a 



* I am indebted to Mr. Walsh for having sent me this extract from 

 a " Journal of the Doings of Cicada septemdecim," by Dr. Hartman. 



f L. Guilding, " Transact. Linn. Soc.," vol. xv, p. 154. 



\ I state this on the authority of Koppen, " Ueber die Heuschrecken 

 in Siidrussland," 1866, p. 32, for I have in vain endeavored to pro 

 cure Korte's work. 



