286 BOTANICAL GAZETTE [ocroBEr 
of technique, fixing, embedding, sectioning, and staining, together 
with the fact that Selaginella spores are sui generis, and one has no 
standard of comparison, make one fearful of drawing conclusions 
from artifacts. Apparently the only way to lessen this danger and 
make results convincing, is to have a very large number of prepara- 
tions killed and treated in various ways, for little critical study can 
be made of the living spore. This has made my investigation an 
exceedingly tedious one, for in the early development of the spore, 
transformation takes place so rapidly that important phases are 
obtained with difficulty, and if not found the danger of misinter- 
pretation is very great. The results of my work fail to confirm 
Firtrne’s theory, nor am I able to accept his description of the 
origin of the coats for the species that I have investigated. It is quite 
certain, I think, that the spore coats of S. rupestris do not lose their 
complete organic connection with the protoplast during growth, and 
I have a growing conviction that to our imperfect technique are 
due the phenomena which gave rise to Firtrne’s theory and — 
described by Firtinc, CAMPBELL, and all other workers in this 
group, including myself. ee 
Very complete series of three species—S. apus, S. Emmeliana, 
and S. rupestris—from the origin of the sporangium to the develop- 
ment of the embryo sporophyte have been studied. Throughout 1s 
history S. rupestris is aberrant, and proves to be a plant of much 
importance and interest, as it has characteristics supposed fe 
peculiar to the seed plants. Normally, and in a greater number 
cases, only two megaspores were found to develop in a spe va 
These miay be two of a tetrad, the others failing to develop after 
division of the mother cell; or, more important still, the mother 
cell may divide only into two spores. These megasports | e 
shed from the megasporangium at all! The female gametophyte 
and the young sporophytes are retained in the old strobilus pie 
the latter have roots, stems, and leaves; then the tissue of the spe 
gium and megasporophyll decays, thus liberating the 
lack only integuments to be seeds. A still further 
megaspores to one is infrequently found. In tracing 
the spores, I again emphasize the fact tha . 
appearance which would suggest that the protoplasm 
reduction of 
the growth of 
is there a0Y 
