1898 ] REGENERATION AS EXHIBITED BY MOSSES IgI 
nated from the ventral surface of the leaf without regard to the 
position which it had occupied in the culture. And further, the 
examination of the whole leaves showed that the protonemata 
originated from the cells lying at each side of the lamella. The 
protonema production from this region was quite general 
throughout the entire length of the leaf. 
In order to determine more closely the origin of the proto- 
nemata, cross sections of the leaf were made. The sections 
showed that they originated from the large cells of the costal 
region lying at the base of the outer lamelle (fig. 32). The 
first growth from the leaf, although the cross-walls were pre- 
dominantly oblique, were decidedly protonemal in character and 
remained so whether the specimens were grown in the light or 
dark. _ The branching was often aggregated in a manner 
altogether unique, as is shown in jig. 30, which may be taken as 
a typical example. In other cases it was more as in ordinary 
protonemata, but the only difference between the protonemata 
grown in the dark and those grown in the light, was that in the 
dark cultures the cells were generally more elongated and 
devoid of chlorophyll, and the branching less. The cell walls 
in both cases were colorless. 
After about five weeks, buds made their appearance, and 
always as modifications of lateral protonemal branches. Con- 
trary to what has been described for all of the preceding 
Species the buds were formed in as great abundance in the dark 
cultures as in the light. In the dark the buds did not attain any 
considerable size on account of the lack of food material, rarely 
reaching a length of 1™. The production of buds in the dark 
is evidently explained from the nature of the leaf. The lamellz 
and the lateral portions of the leaf, since they give rise to no 
protonemata are able to furnish considerable food material which 
can be applied to the growth of leafy shoots. These experi- 
ments show that in one case, at least, light is not necessary for 
developing and unfolding the slumbering ‘“‘Anlage” of which 
Klebs* surmises the existence. 
** Biolog. Centralblatt 13:647. 1893. 
