鬚鯨の多胎及多排卵に就いて

概要

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1. The frequencies of twin pregnancies in the whales were estimated on the basis of International Whaling Statistics No. 3-No. 14 (1932-1940). Number of single pregnancies(A) Number of twin pregnancies(B) B:A % Blue Whale 13, 066 85 I:150 0.6 Fin Whale 14, 660 139 I:110 0.9 Humpback Whale 1, 781 7 I:250 0.4 Sei Whale 445 3 I:150 0.7 The frequencies above mentioned coincide in some degree with those known on horse (0.9%), ox (1.0%), and man (0.7-1.6%). 2. Evidence for the probable occurrence of monozygotic twins has been obtained from the unisexual to bisexual combination (Weinberg's differential method). The percentage of monozygotic twins in fin whales is ca. 0.1%. 3. A case of triplets was observed. Cases of triplets, quadruplets, quintuplet, sextuplets and septuplet pregnancies are found in literature though detailed statements of each case are lacking. 4. Some cases of fin whales with two or three functional corpora lutea in ovaries had one or two foetuses while other cases with more than one functional corpus luteum had no foetus at all; in still other cases was there a single functional corpus luteum in combination with two or three foetuses. Neither the number nor the differences in size of the functional corpora lutea had any bearing on the number or size of the foetuses present.
社団法人日本動物学会の論文
1940-11-15