September, 1922.] SINOTO—IRIS JAPONIC A. 1Q9 



SUMMARY 



1. An extrusion phenomenon of the nuclear substance in Iris 

 japonica is described. The figures of extrusion from one cell into the 



cytoplasm of adjacent cells are found in pollen mother-cells as well 

 as in tapetal-, integumental-, nucellar- and ovarian cells. 



2. The extrusion in the pollen mother-cells is observed to be 

 most active in the synizetic stage and occurs not infrequently in the 

 presynizetic, spireme and hollow-spireme stages and sometimes im- 

 mediately before the diakinesis stage. In somatic cells this process 

 is generally found in the nuclei which are not in division. 



3. The portions of the nucleus which are extruded may be 

 chromatin, synizetic mass, spireme, nucleolus etc. 



4. So far as the observation goes, I am inclined to side with 

 the opinion that this phenomenon is chiefly caused by the fixing 

 fluids and external injuries inflicted by pressure. 



It is with pleasure that I take this occasion to express my 

 sincere thanks to Marquis Yoshichika Tokugawa, the director of 

 the Tokugawa Biological Institute, for all the facilities kindly offered 

 throughout the course of this observation ; my best thanks are also 

 due to Professor Fujn of the Botanical Institute, Science College, 

 Tokyo Imperial University for his kind advice and valuable suggestion. 

 I am much indebted to Viscount Tadamasa Miduno for his kindness 

 in providing the materials used. 



August 1921. The Tokugawa Biological Institute. 



LITERATURE CITED 



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3. (1912). The cytology of Primula Kewensis and of other related Primula 



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