抄録
1. Fourteen varieties of gold-fish common in Japan, together with the Funa and the Hibuna, both of which are known to be the prototypes of the former, have been karyologically investigated in this study. In all these forms the normal or basic number of chromosomes is 94 forming the diploid complement (in the spermatogonium) and 47 for the haploid (in the spermatocytes). The chromosomes are all telomitic and rodshaped showing a slight difference in length. Morphologically the chromosome complex of the Funa and of all the varieties of the gold-fish herein investigated are in complete agreement with one another, both in number and in shape. And thus, there is not the least evidence for the occurrence of the polyploid relationship among the gold-fish varieties.
The karyological relationship between the two allies, the carp., Cyprinus carpio and the Funa, Carassius carassius, (the gold-fish also) has been considered.
2. Occasional occurrence of cells with univalent chromosomes at first metaphase, which is probably due to the failure of the meiotic chromosome pairing, has been observed in nine of the varieties herein deait with. Generally two univalents per cell seem to be most common throughout the forms observed. Four is the most frequent of the higher numbers, but a number as high as eight per cells has been observed. A rough estimate shows that cells with univalents seem to occur in a rather high frequency.
No definite explanation regarding the cause or causes of the formation of univalents has been offered; but the bearing of the chiasma theory and of comparable phenomena investigated in plants on the observations herein recorded has been considered.
