Mr Heape, Notes on the Proportion of the Sexes in Dogs. 131 
With regard to the records now presented. First, I have 
checked the figures supplied to Darwin by collecting the returns 
entered in volumes 7 to 11 of the Greyhound Stud Book for the 
years 1886 — 1892. Secondly, I have tabulated the returns for all 
breeds of dogs published in the Stock Keeper, Kennel Register 
for the years 1889 — 1891. Thirdly, I have abstracted the returns 
published in the Stock Keeper for particular breeds of dogs, 
for those years. Fourthly, I have collected information from 
certain breeders who keep accurate records, of the number of 
males and females actually born in a variety of breeds of dogs ; 
and, as some of these latter records extend over a considerable 
period and give the results of the mating of individual dogs and 
individual bitches, year after year, I have been enabled to record 
the tendency of these individuals to produce a marked proportion 
of offspring of one or the other sex. 
The Greyhound Stud Book. 
Records from the Greyhound Stud Book, vols. 7 (1888) to 11 
(1892) are summarised in Table I. The animals registered during 
that time are tabulated under the year in which they are born. 
Table I. 
Greyhound Stud Book. Registered births per year, 1886—1892. 
Year 
1886 
1887 
1888 
1889 
1890 
1891 
1892 
Dogs 
777 
2278 
1935 
1923 
1781 
940 
40 
Bitches 
666 
1880 
1628 
1666 
1475 
813 
36 
Total 
1443 
4158 
3563 
3589 
3256 
1753 
76 
Dogs per 
100 bitches 
116-6 
121-17 
118-86 
115-43 
120-74 
115-62 
ni-i 
As the Table indicates, pups are not always registered the 
first or even the second year after they are born and for that 
reason the records for the years 1886, 1891, and 1892, in the 
Table, include only a part of the animals which have already been 
or eventually will be recorded for those years. 
Probably, for the same reason, the records for 1890 are also 
incomplete, but judging from the totals obtained for 1887 — 1889, 
