— 21 — 



The experiments with whole plants placed under like 

 conditions as the separated leaves, showed no protonema 

 production whatever from the leaves, and when the tips of 

 the leaves in whole plants were cut away, even then, the 

 leaves formed no protonema. Thus, nothing more or less 

 than a complete Separation of the leaves from the stem would 

 suffice to call forth the power of the leaf cells to grow out 

 into protonema filaments. 



Experiments with leaves grown in blue and red light 

 brought a different result than was found in the case of the 

 Milium leaves. The leaves in the red light produced buds, 

 apparently with as great readiness as in normal Illumination, 

 while in the blue light no buds whatever were formed. When 

 we reflect that it is only in the red light that photosyntax 

 takes place to any extent, the importance of this process as 

 furnishing material for the formation of buds is at once made 

 evident. That the products of photosyntax are necessary for 

 the formation of buds is shown by the fact that leaves grown 

 in a C0 2 free Chamber also produced no buds. The results of 

 there experiments with Bryum leaves accord with those of 

 Schostako witsch 1 for the foliose Jungermannieae , and those 

 with Mnium agree partially with the results for thalloid 

 liverworts. Experiments with Marchantia and other thalloid 

 liverworts showed that regeneration occurred in the dark as 

 well as in the light. 1 have also confirmed these results in 

 the case of Marchantia but in the case of Lophocolea bidentata 

 my results were different than obtained by Schostakowitsch for 

 the same species. I found that the detached leaves produced 

 buds from the marginal cells of the leaf, and that this pro- 

 duction occurs quite abundantly in the dark as well as when 

 the leaves are exposed to light. This result is more in accor- 

 dance with the Observation of Klebs. 2 According to Klebs 

 the leaves of Lophocolea bidentata produced buds in a weak 

 light at an intensity which was not sufficient to produce the 

 germ disk in the case of spore-protonema. Mention may be 



1 Flora, Ergänzungsband: 380—384. 1894. 



2 Biol. Centralblatt 13 : 649. 1893. 



