1903] BRIEFER ARTICLES 229 
grows larger and the Nostoc multiplies, the tree-like upgrowth is pro- 
duced. In other cases of such symbiotic relationships, as Anthoceros, 
there are, likewise, cells growing in from the host plant; but in all 
such cases, so far as I know, these outgrowths originate, not from a 
common base, but separately and at many points. The striking and 
beautiful arrangement in Blasia seems to be confined to it alone. 
SPHAEROCARPUS TERRESTRIS Smith.—I have found this liverwort 
abundantly at Chapel Hill, N. C., Selma, N. C., and Florence, S. C. 
Active spermatozoids were obtained in April of this year from Chapel 
Hill plants, and it is probable that they are liberated during the greater 
Fic. 4.— Blasia pusilla. Section of a large Nostoc Fic. 5.—Section of a 
chamber. X 166. young chamber. X 250. 
part of the growing season, as sporophytes of all ages can be found at 
almost any time.. 
It is the sterile cells of the sporangium, however, that I wish espe- 
cially to mention. They are so peculiar in appearance and behavior 
as to deserve more attention than they seem to have received. These 
cells, though probably the homologues of the elaters of higher forms, 
© not bear the least resemblance to them. They are round, have 
clear cell walls, and contain a good number of bright green chloro- 
phyll granules. These granules retain their bright color almost to the 
time of the ripening of the spore. They then fade slightly to a yellow- 
ish-green, but are still distinctly colored and not the least corroded 
when the spores are quite ripe. If a ripe black sporangium is crushed 
under the microscope, these green cells at once attract attention as 
being totally different from any other sterile cells in the sporangia of 
either liverworts or ferns. They no doubt carry on photosynthesis to 
the last moment. 
An attempt was made to keep these sterile cells alive on wet filter 
