A STUDY OF THE SPORANGIA AND GAMETOPHYTES 
OF SELAGINELLA APUS AND SELAGINELLA 
RUPESTRIS. 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY. 
XXXII. 
FLORENCE May LYON. 
(WITH PLATES V—IX) 
[ Concluded from p. 141.) 
GENERAL DISCUSSION. 
CONSIDERING the phylogenetic importance of the group, the 
literature on the Selaginellaceae is surprisingly scanty. More 
especially is this true of that which treats of the development of 
spore and gametophyte. Some marked discrepancies in essen- 
tial features have appeared in these papers, however, and show 
how much detailed life histories of more species are needed 
before further inferences are drawn as regards the relation of this 
group to others. Only one comparatively full account of a 
single species has yet appeared, Bruchmann’s monograph on 
S. spinulosa, published in 1897, although he gives no account 
whatever of the development of the male gametophyte nor of 
the sporangia. He had much difficulty in obtaining normal 
spores,” and therefore was unable to follow the earliest stages 
of the prothallium in detail. In general, however, he agrees 
with Heinsen and Arnoldi that there is free cell formation within 
the spore, followed by periclinal and anticlinal cell walls, thus 
making a disk-shaped mass of cells in the apical portion of the 
*“Uber die Keimung der Sporen habe ich zu zwei verschiedenen Malen Ver- 
suche angestellt. Das erste Mal sate ich sie gleich nach ihrer Reife (im August) auf 
Torf aus, hielt sie bestandig feucht und schutzte sie im Winter gegen Frost. Die erste 
Keimung weniger Sporen dieser Aussaat bemerkte ich erst nach zwei Jahren, weitere 
keimten dann in dritten Jahre, aber der grosste Teil zeigte selbst nach solcher Zeit 
keine Keimung.” 
170 [SEPTEMBER 
oes entmemesns meee tan 
