304 
THE PRINCIPLES OF 
Part H- 
periods each of four years : this, however, may he accidental ; 
least I can detect nothing of the kind with man in the decenniad 
table in the Registrar's Report for 1866. I may add that certain 
mares, and this holds good with certain cows and with women, 
tend to produce more of one sex than of the other ; Mr. Wright of 
Yeldersley House, informs mo that one of his Arab mares, though 
put seven times to different horses, produced seven fillies. 
Dogs . — During a period of twelve years, from 1857 to 1868, tb® 
births of a large number of greyhounds, throughout England, have 
been sent to the ‘ Field ’ newspaper ; and T am again indebted to 
Mr. Tegetmeier for carefully tabulating the results. The recorded 
births have been 0878, consisting of 3605 males and 3273 female 
that is, in tlio proportion of HOT males to 100 females. Th® 
greatest fluctuations occurred in 1864, when the proportion was as 
95-3 males, and in 1867, as 11 6-3 males to 100 females. The above 
average proportion of 110T to 100 is probably nearly correct in th® 
case of the greyhound, but whether it would hold with other domes- 
ticated breeds is in some degree doubtful. Mr. Cupples has enquired 
from several great breeders of dogs, and finds that all without 
exception believe that females are produced in excess ; he suggests 
that this belief may have arisen from females being less valued and 
the consequent disappointment producing a stronger impressiou on 
the mind. 
>S keep, i he sexes of sheep arc not ascertained by agriculturist® 
until several months after birth, at the period when the males a r ® 
castrated; so that the following returns do not give the proportion® 
at birth. Moreover, I find that several great breeders in Scotland) 
who annually raise some thousand sheep, are firmly convinced that 
a larger proportion of males than of females die during the first on® 
or two years ; therefore the proportion of males would be somewh®*' 
greater at birth than at the age of castration. This is a remarkabl® 
coincidence with what occurs, as we have seen, with mankind, and 
both cases probably depend on some common cause. 1 have re- 
ceived returns from four gentlemen in England who have bred lot®' 
land sheep, chiefly Lcicesters, during the last ten or sixteen year® i 
they amount altogether to 8965 births, consisting of 4407 mad® 3 
and 4558 females ; that is in the proportion of 90 - 7 males to 1 ( ’ ,) 
females. With respect to Cheviot and black-faced sheep bred > n 
Scotland, I have received returns from six breeders, two of them 
a large scale, chiefly for the years 1867-1869, but some of th® 
returns extending hack to 1862. The total number recorded 
amounts to 50,685, consisting of 25,071 males and 25,614 femal eS ’ 
or in the proportion of 97’9 males to 100 females. If we take tb® 
English and Scotch returns together, the total number amount® 
