646 THE DESCENT OF MAN. 



the last chapter on the probable effects of the long-contin- 

 ued use of the vocal organs by the male under the excite- 

 ment of love, rage and jealousy. According to Sir Duncan 

 Gibb, * the voice and the form of the larynx differ in the 

 different races of mankind; but with the Tartars, Chinese, 

 etc., the voice of the male is said not to differ so much 

 from that of the female, as in most other races. 



The capacity and love for singing or music, thougli not 

 a sexual character in man, must not here be passsd over. 

 Although the sounds emitted by animals of all kinds 

 serve many purposes, a strong case can be made out, that 

 the vocal organs were primarily used and perfected in rela- 

 tion to the propagation of the species. Insects and some 

 few spiders are the lowest animals which voluntarily pro- 

 duce any sound; and this is generally effected by the aid of 

 beautifully constructed stridulating organs, which are often 

 confined to the males. The sounds thus produced consist, 

 I believe in all cases, of the same note, repeated rhythmi- 

 cally;! and this is sometimes pleasing even to the ears of 

 man. The chief and, in some cases, exclusive purpose 

 appears to be either to call or charm the opposite sex. 



The sounds produced by fishes are said in some cases to 

 be made only by the males during the breeding-season. All 

 the air-breathing Vertebrata necessarily possess an appa- 

 ratus for inhaling and expelling air, with a pipe capable of 

 being closed at one end. Hence when the primeval mem- 

 bers of this class were strongly excited and their muscles 

 violently contracted, purposeless sounds would almost cer- 

 tainly have been produced; and these, if they proved in 

 any way serviceable, might readily have been modified or 

 intensified by the preservation of properly adapted vari- 

 ations. The lowest Vertebrates which breathe air are 

 Amphibians; and of these, frogs and toads possess vocal 

 organs, which are incessantly used during the breeding.- 

 season, and which are often more highly developed in the 

 male than in the female. The male alone of the tortoise 

 utters a noise, and this only during the season of love. 

 Male alligators roar or bellow during the same season. 

 Every one knows how much birds use their vocal organs as 



*" Journal of the Antliropolog. Soc.," April, 1869, pp. 57, 66. 

 fDr. Scudder, "Notes on Striduiation," in " Proc. Boston Soc. of 

 Nat. Hist.," vol. xi, April, 1868. 



