Physiological Shulies on Schisfostoga osmnudacea. J> 



incident rays, the former make an angle of 35" and the latter an 

 angle of 56°. By calculating the index of the refraction of light 

 of the cell, he obtained '?;=:1.50. 



As to tlie culture of this moss Miyoshi (3) made a series of experi- 

 ments in 1912, and ascertained that it can easily be Cultivated. 



As the Schistostega is always found in a cave where there is but 

 little light, it is interesting to ascertain the intensity of light most 

 suitable for the moss, and the degree of temperature and percent- 

 age of humidity required for its growth. It would further be of 

 interest to know in what artificial nutritive solutions tlie luminous 

 moss grows best, and lastly, whether this moss, in common with 

 some other species, dislikes lime. 



The present work has been carried on in the Botanical In- 

 stitute of tlio Science College of the Imperial University of Tokyo 

 from August, 1914, to July 1915, under the guidance of Prof. M. 

 Miyoshi, to whom I beg to express my sincere thanks. Acknow- 

 ledgments are also due to Mr. T. Kobayashi, Principal of the Heion 

 Primary School ; to Mr. T. Kueoiwa, Head-man of the same 

 village ; to Mr. Pi. Kono, Principal of the Ina Agricultural School ; 

 to Mr. E. Kakegawa ; Principal of the Iwamurada Primary School ; 

 and to Mr. G. Yumoto, all of whom have greatly assisted me 

 in making observations of the moss in its native place. I am 

 also greatly obliged to Mr. T. Yagi, teacher of Natural History at 

 the Nagano Girls' High Scliool, and to Dr. S. Okamura, both of 

 whom have furnished me with valuable material for my studies. 



I. Natural Occurrence of Schistostega osniunclaceci. 



On an excursion to Mt. Komagadake, to the Nakabusa Hot 

 Springs, and to tlie Yutanaka Hot Springs, in the summer of 1914, 



