Notes on the Physiology of the Sporophyte of 

 Funaria and of Mnium. 



Dr. Rodney H. True, 



Wasliin^toii, DC. 



Introductory. 



The results presented in these notes are the outcome of ox- 

 periments performed by the writer at the University of AVis- 

 consin a number of years ago and sup2:)lemented by other studies 

 of more recent date. 



Although the curvature of the seta of manv common mosses 

 and the unsymetric growth of the capsiiles of not a few others 

 are matters of common Observation, students of plant physiology 

 appear to have given but very little attention to the phenome- 

 non. But one author, Wichura (1), seems to have given the sub- 

 ject dose study and his eonclusions were reached without any 

 considerable amount of experimentation. By observing the con- 

 duct of developing sporophytes of Bryum argentewit L. with re- 

 ference to the direction of the strongest illumination when pla- 

 ced in various positions, Wichura came to the conclusion that 

 the Position assumed by the capsules of this species is due to 

 the influence of the direction of the incident light rays. After 

 a few experiments with Bryum argenteum, he ventured the con- 

 clusion that the dii'ection assumed b}" the shoots and leaves of 

 Fissidfnis^ the secund Hypuo, Dicraita and others is likewise de- 

 termined by their relation to the direction and intensity of il- 

 lumination. A marked sensitiveness of the sporophyte to light 

 is also asserted. The possible influence of still other factors in 

 shaping the development of the mosses seems not to have oc- 

 cuiTed to this author. 



Goebel (2), however, points out that our knowledge of.the 

 influence of factors of the environment on the development of 

 the mosses is in a very unsatisfactory state. 



