On the Nuclear Divisions and Partial Sterility 

 in Oenothera LamavcMana, Ser. 1} 



(A Preliminary Note) 



(Contributions to Cytology and Genetics from the Departments 



of Plant-Morphology and of Genetics, Botanical Institute, 



Science College, Tokyo Imperial University. No. 40) 



By 



Yosito Sinoto 



Assistant in Botany 



With 4 Text-Figures 



Thanks to the works of Davis, Gates, Geerts, Lutz, Renner, 

 Stomps and others, the cytology of Oenothera has been greatly 

 advanced during last score of years, yet it will be unsound to say 

 that our knowledge in this respect is already complete. The present 

 research was made by the suggestion of Prof. Fujii to supplement on 

 one hand our knowledge on the cytology of Oenothera, and to see 

 on the other hand whether the plant grown naturalized in Japan 

 since about 1880 and known as Oenothera Lamarckiana, Ser. also 

 threw mutants as in the classical material of de Yries. 



The materials used in this investigation were supplied from the 

 pedigree culture of the plant, grown in the research garden of Prof. 

 Fujii. 2) For the fixation of the materials, Flemming's stronger solu- 

 tion, the chrom-acetic acid solution modified by Dayis(I) and Bouin's 

 fluid were chiefly used with good results. For the staining, Heidenhain's 

 iron-alum-haematoxylin was used as chromosome stains, in association 

 with light green as cytoplasm stain. The sections of the anthers 



1) A more detailed preliminary account of the present research was published 

 in Japanese in this magazine. Vol. XXXIV, pp. (277)— (292) and (301)— (317), 1920. 



2) This pedigree culture was derived from the seeds collected from the plants 

 selfed by Prof. Fujii at the bank of the River Tamagawa in the vicinity of Tokyo, 

 and determined by Mr. Maexno. 



