130 BOTANICAL GAZETTE [ AUGUST 
or H. Muelleri in a genus supposed to be distinguished by hygroscopic spores. 
The retention without comment of the genus Stigmatella (with Sphaerocreas 
as a synonym!), and the extraordinary disposition of the genus I]losporium, 
have also been pointed out by Thaxter in a recent number of the GAZETTE, 
and serve still further to enforce our contention that work of this kind should 
be left to the skilled monographer, and can otherwise only serve to compli- 
cate difficulties already epeeonpianeas —_ when done in connection with a 
hastily prepared and local “ List.” 
NOTES FOR STUDENTS. 
Mr. M. A. BRANNON has completed his study of the structure and devel- 
opment of Grinnellia Americana.s The work was done at Wood's Holl, the 
author occupying the table of the Missouri Botanical Garden. The chief 
points developed in the study may be summed up as follows: This alga is 
distinctly an American marine form, flourishing in quiet waters. There are 
no distinct differences in the vegetative structure of the different fronds, 
which separate from their holdfasts late in summer, and rising to the surface 
effect a wide distribution of the fruiting bodies. The cells are nucleated and 
are connected by protoplasmic pits, except the cells of the procarp, which are 
connected by open pores. Adult plants are very sensitive to intense light 
and increase of temperature, but will not grow in shady places. Mutilated 
plants show great powers of proliferation. The carpospores and tetraspores 
are very favorable for the study of germination, for while they respond 
readily to external conditions they are hardy enough to allow a wide range 
of treatment. The non-motile antherozoids are developed in great numbers 
by the abstriction of the terminal portion of the apical cells of the antheridia. 
The cystocarp begins to develop by the modification and apical growth of a 
joint-thallus-cell. The procarp consists of three cells, and is developed from 
the supporting thallus-cell in the base of the young cystocarp, and its apical 
cell becomes the carpogonium. The fertilized contents of the carpogonium 
are transferred through the open pores connecting the procarpic cells to the 
supporting thallus-cell, which becomes the central one of the five auxiliary 
cells. The trichogyne is often branched, and fusion of the antherozoid with 
it results in great stimulation to the thallus-cell at the base of the procarp, 
the trichogyne itself being a very evanescent organ. The sporiferous fila- 
ments are developed as chains of central cells, from whose branches the 
carpospores arise acropetally.— J. } 
M. Paut PARMENTIER has published an elaborate paper containing the 
results of his researches in the anatomy and taxonomy of ‘‘Onotheracex and 
Ann. Bot. rr: 1-28. Ff. 7 897. 
© Anns Sci. at’ Bot. VIII. 3: Rts 149. pl. 1-6. 1896. 
