Chromosome Observation of Stephania cepharantha HAYATA

1.玉咲ツヅラフヂ(Stephania cepharantha HAYATA)の栽培に於いて, 雄株と雌株の比は栽培観察者の云う如く雌本が少いと云う事は無く, 大体1 : 1に分離す。2.雄株の減数分裂に於いてn=13なる事がたしかめられ形態的に見てXYなる性染色体の存在する事を認めた。3.雌雄両株の体細胞に於いて2n=26なる染色体が算えられた。雄株は24の常染色体とXYなる性染色体を持ち, 雌株は24の常染色体とXXなる性染色体を持つ事が認められた。 / The separating ratio of female and male plants of Stephania cepharantha HAYATA was almost equally expressed. The somatic chromosome numbers of them were both 26. The female plant had 24 autosom and XX chromosomes; in the other hand, the male had 24 autosom and XY chromosomes. At meiosis in P. M. Cs., the number of reduced chromosomes was found to be 13 at polar views in the heterotypic metaphase. One unequal pair of chromosomes was observed in polar and side views of the heterotypic metephase. One of its two members was about 1.5-2.0 larger than the other