10 



Art. 5.— Y. Toda: 



I=Inten.sity of light. i = Relative "Lichtgenuss." 



II. Materials and Methods. 



The materials for the present studies were almost all collected 

 from the caves at Yutanaka. The spores used for germination 

 were obtained at Nakabusa. 



In making the various experiments mentioned below I found 

 it convenient to cultivate the moss in a Petri dish and to put 

 it in a wooden box of 33 cm. x 25 cm. x 20 cm. capacity, with an 

 aperture of 13 cm. square in front. The moss thus gets as much 

 light as in its native place, its beautiful emerald green light being 

 easily seen from outside througli tlie aperture. 



I then put into the Petri dish a piece of brick (or tile) 

 wliich had been completely sterilized, and covered this lightly 

 with the soil on which the moss had been growing. In a short 

 time protonemata were seen to grow all over the brick (or tile), 

 and in about two months many shoots were produced. 



Instead of using a Petri dish I put a whole piece of steriUzed 

 brick into a basin with a little water and deposited on it the 

 protonema-lauen soil. The whole was placed in the box as de- 

 scribed above. 



