Physiological Studies on Schistostega osmundacea. \'J 



gives place to the silvery white light, if the dish is placed in its 

 former position. Tlftl depends on the peculiar form of the cell of 

 the protonema. As the resnlt of ray experiments I have found 

 that the angle of equal intensity of the reflected emerald green 

 light is 50^ — 70°. I am, therefore, inclined to think that the 

 reflected light is emitted from the cell parallel to the incident 

 rays, not only when the latter is paralled to the optical axis of 

 the cell, but also when it makes with the axis tin angle not 

 exceeding 35^^. On this point, however, much further study is 

 necessary before a safe conclusion can be arrived at. 



In addition to what Senn (7) has done in regard to the 

 movement of the chromatophore I have made the following 

 observation : — 



In unilateral light, the chromatophores in the cell of the 

 protonema are gathered in its paraboloidal part, which arrange- 

 ment Senn calls " Escharostrophe " (Fig. 20). If the culturing dish 

 is turned 180 degrees, the chromatophores change their positions 

 in the direction of the new light in one week ; but when the 

 dish is placed in a light whose intensity is from 0.1 to 0.5, the 

 chromatophores are scattered rouncT the cell wall in one day, this 

 arrangement being called " Apostrophe " by Senn (Fig. 3). 



Four weeks after I put the Petri dish in a dark room 

 (May 3rd), I observed the chromatophores in the lens-shaped cell 

 of the protonema to be in " Apostrophe " (Fig. 4). In the case of 

 liquid culture in unilateral light, the chromatophores of the filament- 

 ous cells of the protonema are arranged on the side farthest from 

 the light. This Senn calls " Antistrophe." 



As regards the emerald gi^een light reflected from the lens- 

 shaped cells, which is again seen after the direction of the Hght is 

 changed, I suspect that this phenomenon, besides being dependent 



