the orientation is due to a metabolism gradiant. The second pur- 

 pose qC&^a study of the photro*ropism of the young rhizoids in 

 monochromatic light. It has been shown (^T^jft that they are neg- 

 atively heliotropicjbut the apparatus designed for the polarity 

 experiments made it very easy to answer^, several questions concerning 



tnyfr phenomenon wore definitely. These questions are:(j) What wave- 

 lengchs are responsible for the turning away from a source of white 



lightt (2) What is the role of intensity of the light or is it a 

 matter of quality alone or both? (3) Do all lights which have any 

 efiect at all produce the same negr tive tropism profluced by white ^ 

 light? 



