278 THE DESCENT OF MAN. 



are almost exactly equal in number. I will now give the 

 facts which I have collected with respect to the proportional 

 numbers of the sexes of various animals; and will then 

 briefly discuss how far selection has come into play in- 

 determining the result. 



Horses. Mr. Tegetmeier lias 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 1846 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 tol- 

 erably large, and as they are drawn from all parts of England, dur- 

 ing 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 propor- 

 tions 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 males 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 6,878, consisting of 3,605 males and 3,273 females, that is, in 

 the proportion of 110.1 males to 100 females. The greatest fluctua- 

 tions occurred in 1864, when the proportion was as 95.3 males, and 

 in 1867; as 116.3 males to 100 females. The above average propor- 

 tion of 110.1 to 100 is probably nearly correct in the case of the grey 

 hound, 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 producing a stronger impression on the 

 mind 



Sheep The sexes of sheep are not ascertained by agriculturists 

 until several months after birth, at the period when the males are 



* During eleven years a record was kept of the number of mares which 

 proved barren or prematurely slipped their foals ; and it deserves notice, as 

 showing how infertile these highly nurtured and rather closely interbred ani- 

 mals 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 born, 

 and 743 mares failed to produce offspring. During 1867, 836 males and 902 

 t emaJes were born, and 794 mares failed. 



