186 BOTANICAL GAZETTE [SEPTEMBER 
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 prod- 
ucts of photosyntax are necessary for the formation of buds is 
shown by the fact that leaves grown in a CO,-free chamber also 
produced no buds. The results of these experiments with 
Bryum leaves accord with those of Schostakowitsch* for the 
foliose Jungermanniezx, and those with Mnium agree partially 
with the results for thalloid liverworts. Experiments with Mar- 
chantia and other thalloid liverworts showed that regeneration 
occurred in the dark as well as in the light. I have also con- 
firmed these results in the case of Marchantia, but in the case of 
Lophocolea bidentata my results were different from those 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 production occurs quite abundantly in the 
dark, as well as when the leaves are exposed to light. This 
result is more in accordance with the observation of Klebs.% 
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-protonemata. Men- 
tion may be made here of the cultures of Plagiochila aspleniotdes 
leaves. Greenhouse specimens showing every appearance of 
vigor were used, and the cultures were kept for over two 
months, but although the leaves remained green and vigorous, 
no sign of any bud or rhizoid production was observed. This 
was one of the species which Schostakowitsch grew successfully, 
and it is apparent from these results that there are conditions of 
the plant, when although apparently vigorous, the power of 
regeneration may be suppressed. 
The defoliated stems of Bryum produced some protonemata 
direct from the region of the leaf axil, but in the case of speci- 
mens grown in the dark no distinct protonema growths were 
noted. The abundance of production was much less than in the 
case of Kunaria hygrometrica. The paraphyses here also were 
*4 Flora, Erganzungsband 1894: 380-384. *5 Biol. Centralblatt 13 : 649. 1893- 
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