284 THE DESCENT OF MAN 



tlie male had tlie power to defend the female during the 

 pairing- season, as occurs with some of the higher animals, 

 or aided her in providing for the young. The same princi- 

 ples would apply if each sex preferred and selected certain 

 individuals of the opposite sex; supposing that they selected 

 not only the more attractive, but likewise the more vigorous 

 individuals. 



Numerical Proportion of the Two Sexes. — I have remarked 

 that sexual selection would be a simple affair if the males 

 were considerably more numerous than the females. Hence 

 I was led to investigate, as far as I could, the proportions 

 between the two sexes of as many animals as possible; but 

 the materials are scanty. I will here give only a brief ab- 

 stract of the results, retaining the details for a supplement- 

 ary discussion, so as not to interfere with the course of my 

 argument. Domesticated animals alone afford the means of 

 ascertaining the proportional numbers at birth; but no rec- 

 ords have been specially kept for this purpose. By indirect 

 means, however, I have collected a considerable body of sta- 

 tistics, from which it appears that with most of our domestic 

 animals the sexes are nearly equal at birth. Thus 25,560 

 births of race-horses have been recorded during twenty-one 

 years, and the male births were to the female births as 99. 7 

 to 100. In greyhounds the inequality is greater than with 

 any other animal, for out of 6, 878 births during twelve years, 

 the male births were to the female as 110. 1 to 100. It is, 

 however, in some degree doubtful whether it is safe to infer 

 that the proportion would be the same under natural condi- 

 tions as under domestication; for slight and unknown dif- 

 ferences in the conditions affect the proportion of the sexes. 

 Thus with mankind, the inale births in England are as 104.5, 

 in Eussia as 108. 9, and with the Jews of Livonia as 120 to 

 100 female births. But I shall recur to this curious point 

 of the excess of male births in the supplement to this 

 chapter. At the Cape of Good Hope, however, male 

 children of European extraction have been born during 



