18 Art. 5.— Y. Toda : 



on the movement of the chromatophores, is also caused by the 

 action of the filament which contains a group of spherical cells, 

 that is, the cells of the protonema spread on the surface, appear to 

 change their orientation on the turning of the filament. 



On December 10th, 1914, I took five wooden boxes, 15 cm. 

 square, with a piece of red, yellow% green, blue, and violet glass 

 respectively on the front, and covered the Petki dishes containing 

 the moss with these boxes. In comparing the results of different 

 cultures in different rays, all of unilateral light, I found on the 

 24th of February, 1915, that the moss throve best in the violet, 

 tlie blue, and the yellow light. In the red, it did not thrive well, 

 and in the green least of all. The formation of starch in the 

 chloroplast in the cell of the protonema I found to be greatest 

 in the blue and in the yellow light, the red ranking next, the green 

 following. 



In tlie violet and the blue, 7 — 10 days were required for the 

 reflection of the emerald green light to reappear after the change 

 in the direction of the light; in the yellow 10 — 14 days; in the 

 red a little more ; while in the green hardly any light was seen 

 reflected after the lapse of even as many as 20 days. I used for 

 my experiment two sets of the double glass cylindrical apparatus 

 designed by Prof. Miyoshi^^ to suit the bubble -counting method, 

 filling one set with an ammoniacal solution of copper hydrate, and 

 the other with a solution of potassium bichromate. In each set, I 

 placed, on the 16th of April, 1915, a Petri dish containing the 

 protonema, covering the former set with a piece of blue glass and 

 the latter with red glass, and pasting black paper on the back of 

 each, I let the light come only from the front. On May 16th, the 



1) MiYosHi M. : Experimental botany (Japanese edition). 2ad Ed. 1908. p. 415. Fig. 219. 



