460 
SISTER M. ELLEN 
than the return of growing weather in March, the question arises as to 
whether the first divisions, which had already taken place in the fall, 
might have been thought by him to be spring divisions. The fact that the 
times stated for tetrad formation, stalk elongation, spore dispersal, and 
other activities of the plant, as observed by Bolleter, seem to be approxi- 
mately the same as in material studied by me, makes it seem still more 
likely than his statement regarding the time of the first divisions of the 
spores is erroneous. 
The partition walls when first formed between the cells of a sporeling 
are notably thin, and with Flemming's triple stain are scarcely discerniible 
Light green, when used instead of Orange G, however, gave them sufficient 
prominence to make them easily visible. After the first three divisons. 
have occurred (fig. 6), there is a slight enlargement of the cells, a thickening 
of the partition walls, and a deposition of starch (fig. 7). 
Material collected on March 7 showed no signs of change as compared 
with the late fall and winter collections, but on the 19th of March, the first 
really spring-like day, further divisions within the spore wall had taken 
place. Division stages were also observed in some of the preparations from 
this material. Within a few days the sporelings showed as many as ten 
or eleven cells in a median longitudinal section (fig. 8). Again there was a 
stoppage of cell division, and a period followed during which time there 
was growth and rapid development of chlorophyll within the cells. The 
next series of cell divisions took place early in April, and by April 9 the 
sporelings showed as many as seventeen cells in a median longitudinal 
section (fig. 9). It was noted that each period of cell division in the spore- 
lings was preceded by growth and by the production and storage of starch. 
During the latter part of this series of divisions, but more especially 
after the process was completed, the stalks of the carpocephala elongated 
rapidly until the sessile heads were raised five or six centimeters above the 
thallus. This rapid elongation is due, as is stated by Cavers (2) and Bolleter 
(i), to the growth of the cells already formed rather than to cell divisions 
within the stalks. 
The sporelings which were sown immediately after dispersal almost 
without exception promptly resumed their development, and within less 
than twenty-four hours the majority showed at least two, and many of 
them showed three rhizoids (figs. 10, 11). A bud destined to develop into 
a thallus {h, fig. 12), usually appeared within four or five days, and a little 
later, secondary rhizoids were developed from the growing thallus (fig. 13). 
The above description holds for those sporelings which were placed in 
weak, as well as for those placed in strong, illumination. But in the later 
stages there was a relatively rapid and profuse development of both thalli 
and secondary rhizoids in the material which was placed in strong illumina- 
tion (PI. XXXV, figs. 14, 15). 
To test the efifect of drying, some of the sporelings which had been kept 
