Chap. VIII. SEXUAL SELECTION. 207 



more frequently present sexual differences than almost 

 any other group of mammals, especially in their weapons, 

 but likewise in other characters. Most deer, cattle, and 

 sheep are polygamous; as are most antelopes, though 

 some of the latter are monogamous. Sir Andrew 

 Smith, in speaking of the antelopes of South Africa, 

 says that in herds of about a dozen there was rarely 

 more than one mature male. The Asiatic Antilope 

 saiga appears to be the most inordinate polygamist 

 in the world; for Pallas 6 states that the male drives 

 away all rivals, and collects a herd of about a hundred, 

 consisting of females and kids : the female is hornless 

 and has softer hair, but does not otherwise differ much 

 from the male. The horse is polygamous, but, except 

 in his greater size and in the proportions of his body, 

 differs but little from the mare. The wild boar, in his 

 great tusks and some other characters, presents well- 

 marked sexual characters ; in Europe and in India he 

 leads a solitary life, except during the breeding-season ; 

 but at this season he consorts in India with several 

 females, as Sir W. Elliot, who has had large experience 

 in observing this animal, believes : whether this holds 

 good in Europe is doubtful, but is supported by some 

 statements. The adult male Indian elephant, like the 

 boar, passes much of his time in solitude; but when 

 associating with others, "it is rare to find," as Dr. 

 Campbell states, " more than one male with a whole 

 < ; herd of females." The larger males expel or kill the 

 smaller and weaker ones. The male differs from the 

 female by his immense tusks and greater size, strength, 

 and endurance ; so great is the difference in these latter 



6 Pallas, ' Spicilegia Zoolog/ Fasc. xii. 1777, p. 29. Sir Andrew 

 Smith, ' Illustrations of the Zoology of S. Africa/ 1849, pi. 29, on the 

 Kobus. Owen, in his 'Anatomy of Vertebrates ' (vol. iii. 18l8, p. 633) 

 gives a table incidentally showing which species of Antelopes pair and 

 which are gregarious. 



