Chap. VIII.] SEXUAL SELECTION. 29£ 



convinced that a larger proportion of males than of females die 

 during the first one or two years ; therefore the proportion of 

 males would be somewhat greater at birth than at the age of cas- 

 tration. This is a remarkable coincidence with what occurs, as 

 we have seen, with mankind, and both cases probably depend on 

 some common cause. I have received returns from four gentle- 

 men in England who have bred lowland sheep, chiefly Leicesters, 

 during the last ten or sixteen years; they amount altogether to 

 8,965 births, consisting of 4,407 males and 4,558 females; that is, 

 in the proportion of 96.7 males to 100 females. "With respect to 

 Cheviot and black-faced sheep bred in Scotland, I have received 

 returns from six breeders, two of them on a large scale, chiefly 

 for the years 1867-1869, but some of the returns extending back 

 to 1862. The total number recorded amounts # to 50,685, consist- 

 ing of 25,071 males and 25,614 females, or in the proportion of 

 97.9 males to 100 females. If we take the English and Scotch 

 returns together, the total number amounts to 59,650, consisting 

 of 29,478 males and 30,172 females, or as 97.7 to 100. So that 

 with sheep at the age of castration the females are certainly in 

 excess of the males; but whether this would hold good at birth 

 is doubtful, owing to the greater liability in the males to early 

 death. 41 



Of Cattle I have received returns from nine gentlemen of 982 

 births, too few to be trusted ; these consisted of 477 bull-calves 

 and 505 cow-calves; i. e., in the proportion of 94.4 males to 100 

 females. The Rev. W. D. Fox informs me that in 1867 out of 84 

 calves bom on a farm in Derbyshire only one was a bull. Mr. 

 Harrison Weir writes to me that he has inquired from several 

 breeders of Pigs, and most of them estimate the male to the fe- 

 male births as about 7 to 6. This same gentleman has bred Rab- 

 bits for many years, and has noticed that a far greater number of 

 bucks are produced than does. 



41 I am much indebted to Mr. Cupples for having procured for me the 

 above returns from Scotland, as well as some of the following returns on 

 cattle. Mr. R. Elliot, of Laighwood, first called my attention to the 

 premature deaths of the males — a statement subsequently confirmed by 

 Mr. Aitchison and others. To this latter gentleman, and to Mr. Payau, 

 I owe my thanks for the larger returns on sheep. 



