犬の乳頭式に関する発生学的並びに解剖学的研究第一報犬胎児について

抄録

The mammary formula of the canine fetus has not been described in the literature. Therefore, author studied the variation of the mammary formula, the teat number and teat dislocation, in a sum total of 24 canine fetuses. The results are summarized as follows.
The mammary formula was divided into 5 types. The most standard type, 2+2+1=10, had a frequency of about 50 per cent. The mean value (±standard error) of the teat number was 9.458±0.055. From those results, it was found that the mammary formula of dogs in the embryological condition is the many-mammae type in general.
Teat dislocation occurred frequently in the anterior abdominal and inguinal regions.