1896 | CYSTOCARP OF GRIFFITHSIA 45 
In connection with this study the question naturally arises as 
to the proper limitations in the use of the term “auxiliary cell.” 
Schmitz applies it to cells performing slightly different func- 
tions. 1. To acell of the thallus or of the carpogenic branch which 
grows rich in protoplasm and then gives up its contents to an 
ooblastema thread, thus supplying it with the extra nutriment 
necessary for the production of spores, as in Naccaria and Petro- 
ces. 2. Toacell which enters into conjugation with the ferti- 
lized carpogonium or with a filament arising from it, and which 
after thus receiving the influence of fertilization, itself cuts off a 
cell from which the sporogenous filaments arise, as observed by 
him in Gleosiphonia. It is in this sense that he applies the term 
to the supporting cell in Griffithsia, assuming that conjugation 
takes place between it and the carpogonium, either directly or 
by means of a short conjugation process. Mr. Davis,’ in his 
description of Champia parvula, applies the term to ordinary 
thallus cells, which, so far as he has observed, do not fuse with 
any of the cells directly concerned with the development of the 
cystocarp, but which give rise to the wall of the cystocarp, after 
a modification of their contents and union with one another and 
with the supporting cell by means of protoplasmic processes. It 
seems very doubtful if such a use of the term is in accordance 
with Schmitz’s application of it. It would seem much less ques- 
tionable to apply it in Griffithsia to the supporting cell, which 
gives rise to the placental cell, even though the influence of fer- 
tilization is transmitted through the cells of the carpogenic 
branch by a broadening of pit connections or the absorption of 
walls instead of by means of conjugation between the carpogo- 
nium and the supporting cell. Janczewski following Bornet and 
Thuret applies the term carpogenic cell to the cell which gives 
rise to the spores, whether it be the carpogonium, which these 
writers regard as a part of the “trichophoric apparatus,” or some 
other cell which performs the function of spore production. 
Later writers limit the application of carpogenic cell to the cell 
directly beneath the trichogyne, whatever its fate after fertiliza- 
** Development of the cystocarp of Champia parvula, Bor. Gaz. 21: 109. 1896. 
