On the relation of the duration of pregnancy to size of litter and other characters in bitches.
成果类型：
Article
署名作者：
Pearson, M; Pearson, K
刊物名称：
BIOMETRIKA
ISSN/ISSBN：
0006-3444
DOI：
10.2307/2332099
发表日期：
1931
页码：
309323
关键词：
摘要：
In Pomeranians, Pekinese and crosses between them, the mean duration of pregnancy is about 60 days, and the standard deviation about 3 days. The correlation of size of litter with duration of pregnancy is [long dash].45 [plus or minus].05; with order of pregnancy, [long dash].05 [plus or minus].05; with age, [long dash].17 [plus or minus].06. In the first case, size of litter is probably the causal factor and hastens the end of gestation. The correlation of duration with order of pregnancy is + .18 [plus or minus] .06; the regression is nonlinear, the correlation ratio of duration on order being .38. The correlation of age with order of pregnancy is + .80 [plus or minus].02; with duration, + .15 [plus or minus] .06. None of the factors considered explains the variation in duration. Can it be that this duration is individual and possibly an inherited character? If so it would be of evolutionary importance..