2g2 THE BOTANICAL MAGAZTSE. tvoi. xxxv. no. 417. 



heredity substances to the opposite poles is there unlike the usual 

 homeotvpic division as a rule, decidedly unequal -in the second 

 division. Once I met vs^ith the case belonging to the Rosenbeerg's 

 Dro sera-type. 



4. Behavior of chromosomes and the origin of variations. On 

 account of the irregularity of the chromosomes distribution in the 

 meiotic division of the pollen mother cell, the pollen grains of the F, 

 plant between Papaver orientate and P. somniferiim are different from 

 each other in the heredity substances they contain. If even a 

 part of these pollen grains were fertile, then the offsprings of F, 

 plant will show proportions of the combination of the factors 

 different from the Mendelian expectation, and the number of different 

 kinds of offsprings will be richer than in the Mendelian expectation.. 



It is possible that such a process due to hybridization takes 

 place sometimes in nature, and becomes a cause of the origin of 

 variations. 



The large pollen grains, whose cell nuclei were produced by the 

 fusion of two nuclei in the meiotic division, are provided with diploid 

 nuclei. Sperm cell from such pollen grains have the possibility of 

 producing a triploid or tetraploid plant in mating with a haploid or 

 diploid egg. 



The above mentioned irregularities of the chromosome distribution 

 will be a concrete case belonging to the fourth item of the causes 

 of the origin of new forms or species postulated by Fujii (1920 ) 



5. Amitosis-like figures in the meiotic nuclei. The two nuclei 

 in the process of fusion in the first or second meiotic division 

 present the figure very much like that which has been often 

 described as amitosis Quel, Ticshler, Osawa etc.). Sakamura (1920) 

 observed the similar nuclei in the root cells and the pollen mother 

 cells of Vicia faba treated with chloralhydrate and other agents, and 

 he regarded them as the reconstruction figures of mitotic nuclei which 

 were temporarily disturbed on the way of division, and not as the 

 nuclei in the process of amitosis. I follow the latter author in 

 regarding them not as amitosis. I take them for the fusion of 

 nuclei, and it may be added here, that such a process may well 

 occur in nature under several external and internal influences acted 

 on the plasma in the meiotic phase. 



6. Sterility of hybrids. As a cause of the sterility in hybrid plants, 

 many authors, e. g., Juel (1900), Tischler (1908), Bateson (1907), 

 and Gates (1907, 1909), pointed out the irregular behavior of the 



