103 



(5) When cultivated on gypsum or pure agar-agar in a moist chamber 

 under various temperatures varying between 20° and 37°, asco- 

 spores are formed neither in our yeast-cells nor in these of " moto"- 

 liquid. 



(6) When cultivated on a piece of boiled potato, they both form 

 grayish white colonies, rising above the surface of the nutrient 

 medium. Both will never produce mycelium and always multiply 

 by budding like common beer-yeast. 



(7) When cultivated in a test-tube filled with nutrient gelatine, they 

 both form colonies which are broadest at the surface and are nar- 

 rower towards the lower level (so-called " Nagelkultur "). 



To the above seven proofs described by me toward the identity of 

 our yeast-cells and those of " tanekoji " two remarkable facts, which 

 are retained by our sake-brewers as secrets may be added : 



(1) In our country, many sake-brewers seem to use spores of our 

 fungus for manufacturing " tanekoji" used in sake-brewery. 1 } 



(2) The method called " mizumoto " by sake-brewers consists in 

 soaking a quantity of rice-grains in water for nearly one week and 

 then using this water for the purpose of fermentation. In this 

 case, spores covering glumes of rice-grains so abundantly will sink 

 to the bottom of water, produce yeast-cells and so set up fermen- 

 tation. 



From the above considerations, therefore, we may conclude safely 

 that yeast-cells of our sake-brewery originate from the spores of 

 Spkacelotheca virens commonly called Ustilago virens. 



D I am thankful to Prof. M. Shirai who has kiuJly told me this fact 



