240 THE DESCENT OP MAN. 



sexes of various animals; and will then briefly discuss how far 

 selection has come into play in determining the result. 



Horses, — Mr. Tegetmeier has been so kind as to tabulate for me 

 from the 'Racing Calendar' the births of race-horses during a 

 period of twenty-one years, viz., from 1S46 to 1867; 1849 being 

 omitted, as no returns were that year published. The total births 

 were 25,560,°' consisting of 12,763 males and 12,797 females, or in 

 the proportion of 99.7 males to 100 females. As these numbers 

 are tolerably large, and as they are drawn from all parts of 

 England, during several years, we may with much confidence 

 conclude that with the domestic horse, or at least with the race- 

 horse, the two sexes are produced in almost equal numbers. The 

 fluctuations in the proportions during successive years are closely 

 like those which occur with mankind, when a small and thinly- 

 populated area is considered; thus in 1856 the male horses were 

 as 107.1, and in 1867 as only 92.6 to 100 females. In the tabulated 

 returns the proportions vary in cycles, for the mal3s exceeded the 

 females during six successive years; and the females exceeded the 

 males during two periods each of four years: this, however, may 

 be accidental; at least I can detect nothing of the kind with man 

 in the decennial table in the Registrar's Report for 1866. 



Dogs. — During a period of twelve years, from 1857 to 1868, the 

 births of a large number of greyhounds, throughout England, 

 were sent to the 'Field' newspaper; and I am again indebted to 

 Mr. Tegetmeier for carefully tabulating the results. The recorded 

 births were 6878, consisting of 3605 males and 3273 females, that 

 is, in the proportion of 110.1 males to 100 females. The greatest 

 fluctuations occurred in 1864, when the proportion was as 95.3 

 males, and in 1867, as 116.3 males to 100 females. The above 

 average proportion of 110.1 to 100 is probably nearly correct in 

 the case of the greyhound, but whether it would hold with other 

 domesticated breeds is in some degree doubtful. Mr. Cupples 

 has inquired from several great breeders of dogs, and finds that 

 all without exception believe that females are produced in excess; 

 but he suggests that this belief may have arisen from females 

 being less valued, and from the consequent disappointment pro- 

 ducing a stronger impression on the mind. 



^ During eleven years a record was kept of the number of mares 

 which proved barren or prematurely slipped their foals; and it de- 

 serves notice, as showing how infertile these highly-nurtured and 

 rather closely-interbred animals have become, that not far from one- 

 third of the mares failed to produce living foals. Thus during 1866, 

 809 male colts and 816 female colts were bom, and 743 mares failed to 

 produce offspring. During 1867, 836 males and 902 females were born, 

 and 794 mares failed. 



