530 THE DESCENT OF MAN. 



dalis), however, is exceptional, for tlie colors of the female, com- 

 pared with those of the male, are "moins apparentes, le fauve 

 "etant plus terne, le blanc moins pur, les raies ayant moins de 

 "largeur et les taches moins de diamStre."- The sexes of the 

 allied Felis mitis also differ, hut in a less degree; the general 

 hues of the female being rather paler than in the male, with 

 the spots less black. The marine Carnivora or seals, on the other 

 hand, sometimes differ considerably in color, and they present, 

 as we have already seen, other remarkable sexual differences. 

 Thus the male of the Otaria nigrescens of the southern hemi- 

 sphere is of a rich brown shade above; whilst the female, who ac- 

 quires her adult tints earlier in life than the male, is dark-gray 

 above, the young of both sexes being of a deep chocolate color. The 

 male of the northern Phoca groenlandica is tawny gray, with a 

 curious saddle-shaped dark mark on the back; the female is 

 much smaller, and has a very different appearance, being "dull 

 "white or yellowish straw-color, with a tawny hue on the hack;" 

 the young at first are pure white, and can "hardly he distinguished 

 "among the icy hummocks and snow, their color thus acting as a 

 "protection. "=" 



With Ruminants sexual differences of color occur more com- 

 monly than in any other order. A difference of this kind is gen- 

 eral in the Strepsicerene antelopes; thus the male nilghau (Por- 

 tax picta) is bluish-gray and much darker than the female, with 

 the square white patch on the throat, the white marks on the 

 fetlocks, and the black spots on the ears all much more distinct. 

 We have seen that in this species the crests and tufts of hair are 

 likewise more developed in the male than in the hornless female. 

 I am informed by Mr. Blyth that the male, without shedding 

 his hair, periodically becomes darker during the breeding-season. 

 Young males cannot be distinguished from young females until 

 about twelve months old; and if the male is emasculated before 

 this period, he never, according to the same authority, changes 

 color. TJie importance of this latter fact, as evidence that the 

 coloring of the Portax is of sexual origin becomes obvious, when 

 we hear'^* that neither the red summer-coat nor the blue winter- 

 coat of the Virginian deer is at all affected by emasculation. With 

 most or all of the highly-ornamented species of Tragelaphus the 

 males are darker than the hornless females, and their crests of 



- Besmarest, 'Mammalogie,' 1S20, p. 220. On Felis mitis Rengger, 

 Ibid. s. 194. 



■a Dr. Murie on the Otaria, 'Proc. Zool. Soc' 1869, p. 108. Mr. R. 

 Brown, on the P. groenlandica, ibid. 1868, p. 417. See, also, on the colors 

 of seals, Desmarest, ibid. p. 243, 249. 



'■^ Judge Caton, in 'Trans. Ottawa Acad, of Nat. Sciences,' 1868, p. 4. 



