280 THE DESCENT OP MAN. 



"to alight near a male -while he was uttering his clanging notes." 

 Fritz Miiller writes to me from S. Brazil that he has often lis- 

 tened to a musical contest between two or three males of a species 

 with a particularly loud voice, seated at a considerable distance 

 from each other: as soon as one had finished his song, another 

 immediately began, and then another. As there is so much ri- 

 valry 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 dif- 

 ferences betv/een the sexes of the Homoptera. Mr. Douglas in- 

 forms me that there are three British species, in which the male 

 is black or marked with black bands, whilst the females are pale- 

 colored or obscure. 



Order, 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 

 Locustidffl for which there is no equivalent English name, and 

 the Acridiidse or grasshoppers. The stridulation produced by 

 some of the Locustid» is so loud that it can be heard during the 

 night at the distance of a mile;-' 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 Russia, Korte has given=' an 

 interesting case of selection by the female of a male. The males 

 of this species (Pachytylus migratorius) whilst coupled with the 

 female stridulate from anger or jealousy, if approached by other 

 males. The house-cricket when surprised at night uses its voice 

 to warn its fellows.^" In North America the Katy-did (Platy- 

 phyllum concavum, one of the Locustidas) is described^ as mount- 

 ing on the upper branches of a tree, and in the evening lieginning 

 "his noisy babble, while rival notes issue from the neighboring 

 "trees, and the groves resound with the call of Katy-did-she-did 

 "the live-long night." Mr. Bates, in speaking of the European 

 field-cricket (one of the Achetidse), says, "the male has been ob- 

 "served to place himself in the evening at the entrance of his 

 "burrow, and stridulate until a female approaches, when the 

 "louder notes are succeeded by a more subdued tone, whilst the 



2^ L. Gullding, 'Transact Linn. Soc' vol. xv. p, 154. 



'^ I state this on the authority of Koppen, 'Ueber die Heuschrecken 

 in Sudrussland,' 1866, p. 32, for I have in vain endeavored to procure 

 Korte' s work. 



-" Gilbert White, 'Nat. Hist, of Selborne,' vol. ii. 1825, p. 262. 



™ Harris, 'Insects of New England," 1842, p. 128. 



