132 Mr Heape, Notes on the Proportion of the Sexes in Dogs. 
but few remain to be added to that year’s total and the results 
for the four years 1887 — 1890 may be taken as typical. 
The proportion of dogs for these four years varies between 
11543 and 121T7, an average of 11907 ; while if all the animals 
registered are included in the calculation the average works out 
at 118'5, as against HOT given by Darwin, a difference of 8‘4 in 
favour of dog pups. 
In Table II, the numbers are given in accordance with the 
month of birth, and, roughly, of the month of conception. 
Table II. 
Greyhound Stud Book. Registered births per month for years 
1886—1892. 
Month 
of 
birth 
Dogs 
Bitches 
Total 
Dogs 
per 100 
bitches 
Extreme 
variation 
during years 
1887—1890. 
Dogs per 
100 bitches 
Difference 
Mean of 
variation 
during years 
1887—1890. 
Dogs per 
100 bitches 
Month 
of con- 
ception 
Jan. 
1031 
805 
1836 
128-07 
123-134 
11 
128-5 
Nov. 
Feb. 
988 
867 
1855 
113-96 
95—127 
32 
111-0 
Dec. 
Mar. 
1280 
1127 
2407 
113-57 
107—117 
10 
112-0 
Jan. 
Apr. 
1610 
1378 
2988 
116-84 
111—127 
16 
119-0 
Feb. 
May 
1685 
1414 
3099 
119-16 
111—124 
13 
117-5 
Mar. 
June 
1326 
1155 
2481 
114-8 
112—121 
9 
116-5 
Apr. 
July 
938 
761 
1699 
123-26 
95—130 
35 
112-5 
May 
Aug. 
432 
363 
795 
119-0 
93—149 
56 
121-0 
June 
Sept. 
202 
182 
384 
110-99 
96—130 
34 
113-0 
July 
Oct. 
94 
65 
159 
144-61 
115—187 
72 
151-0 
Aug. 
Nov. 
45 
25 
70 
180-0 
133—200 
67 
166-5 
Sept. 
Dec. 
43 
22 
65 
195-45 
171 — 500 
329 
335-5 
Oct. 
Totals 
9674 
8164 
17838 
118-5 
115—121 
6 
118-0 
According to Stonehenge {The dog in health and disease, 
1887) the best time of year for breeding is from April to 
September, the cold of winter being unfavourable for the develop- 
ment of young puppies ; but for sporting reasons Greyhounds are 
usually bred earlier in the year, because their age is reckoned 
from the 1st January and the earlier they are born the better 
chance they have in competition with their fellows of the same 
year. Thus, this Table shows that the four months, March to 
June, are the months during which most births are recorded and, 
