SEX. 317 



years ; " * and it is at least probable that this is true 

 with other classes of animals. 



If with sheep the enumeration of the sexes takes 

 place at the time of castration of the rams, several 

 months after birth, which is the common practice, the 

 proportion of males, as pointed out by Mr. Darwin, 

 would be too small. This element of error should not 

 be overlooked in statistics of animals derived from 

 published records of births, as the animals that die 

 young, including the still-born, are not likely to be 

 recorded ; and of these the largest proportion will in 

 all probability be males. 



M. Tegetmeier tabulated for Mr. Darwin the births 

 of a large number of greyhounds that had, during a 

 period of twelve years, been sent to the Field news- 

 paper. 



" The recorded births have been 6,878, consisting 

 of 3,605 males and 3,273 females ; that is, in the pro- 

 portion 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." 3 



" "With respect to fowl," Mr. Darwin " received 

 only one account, namely, that out of 1,001 chickens 

 of a highly-bred stock of Cochins, reared during eight 

 years by Mr. Stretch, 487 proved males and 514 fe- 

 males ; i. e., as 94.7 to 100. 



" In regard to domestic pigeons, there is good evi- 

 dence that the males are produced in excess, or that 

 their lives are longer ; for these birds invariably pair, 



1 "Descent of Man," vol. L, p. 294, 



2 Ibid. 



