638 THE DESCENT OF MAN. 



than the females. They lead the troop, and, when there is 

 danger, come to the front. We thus see how close is the 

 parallelism between the sexual differences of man and the 

 Quadrumana. With some few species, however, as with 

 certain baboons, the orang and the gorilla, there is a con- 

 siderably greater difference between the sexes, as in the 

 size of the canine teeth, in the development and color of 

 the hair, and especially in the color of the naked parts of 

 the skin, than in mankind. 



All the secondary sexual characters of man are highly 

 variable, even within the limits of the same race; and they 

 differ much in the several races. These two rules hold 

 good generally throughout the animal kingdom. In the 

 excellent observations made on board the ' ' Novara,"* the 

 male Australians were found to exceed the females by only 

 sixty-five millimeters in height, while with the Javans the 

 average excess was two hundred and eighteen millimeters; 

 so that in this latter race the difference in height between the 

 sexes is more than thrice as great as with the Australians. 

 Numerous measurements were carefully made of the stat- 

 ure, the circumference of the neck and chest, the length of 

 the back-bone and of the arms, in various races; and 

 nearly all these measurements show that the males differ 

 much more from one another than do the females. This 

 fact indicates that, as far as these characters are con- 

 cerned, it is the male which has been chiefly modified, 

 since the several races diverged from their common stock. 



The development of the beard and the hairiness of the 

 body differ remarkably in the men of distinct races, and 

 even in different tribes or families of the same race. We 

 Europeans see this among ourselves. In the Island of St. 

 Kilda, according to Martin, f the men do not acquire 

 beards until the age of thirty or upward, and even 

 then the beards are very thin. On the Europaeo- Asiatic 

 continent, beards prevail until we pass beyond India ; 

 though with the natives of Ceylon they are often absent, 

 as was noticed in ancient times by Diodorus. J Eastward 



* The results were deduced by Dr. Weisbacli from the measure- 

 ments made bv Drs. K. Scherzer and Schwarz. See " Reise der 

 ' Novara :' Anthropolog. Theil," 1867, ss. 216, 231, 234, 236. 239. 269. 



f "Voyage to St. Kilda" (3d edit., 1753), p. 37. 



\ Sir J. E. Tennent, ''Ceylon," vol. ii, 1859, p. 107. 



