1 8 Brannon . — The Structure and Development of 
as noted, is the centre of growth of the sporiferous filaments, 
and the four adjacent cells receive and supply food-material 
for the development of the sporiferous tissue. In all prepara- 
tions of a certain stage it was observed that the central cell 
gave rise to an upper and a lower daughter-cell (Fig. 20 b, c ). 
These cells contained the same dense, yellowish, protoplasmic 
contents which characterized the cell from which they came. 
The daughter-cells, resulting from the division of the upper 
cell (Fig. 2 6 d) multiply rapidly and soon form a papilla (pa) 
of four to six cells extending from the floor obliquely into the 
cavity of the cystocarp. The plane of cleavage in the cells of 
the papilla is not regular but angular and concave on the 
upper surface of older, and convex on the lower surface of 
younger cells (Fig. 18). Marginal cells are cut off from the 
surface of these and give rise to most of the sporiferous 
filaments (Fig. 23). All of these cells are connected by pits 
and contain the same dense, yellowish, protoplasmic contents 
which characterized the auxiliary cells. 
Sporiferous filaments continue to originate at different 
times, so that in a median longitudinal section of a partially 
mature cystocarp fully developed spores may be found on one 
side, and half mature to very young ones on the other (Fig. 22). 
The sporiferous filaments have a somewhat unique, though 
uniform, method of development. They usually grow in the 
form of a central chain of cells, from each unit of which 
a whorl of branches is developed consisting of two to three 
cells (Fig. 24). Primarily, the cells of each branch are 
connected by long protoplasmic filaments (Fig. 18 pi), but the 
cells gradually enlarge until this neck-like connexion is so 
abbreviated that they are almost in contact, showing merely 
a simple protoplasmic pit in the very short connexion between 
their walls (Fig. 23/). These enlarged cells become densely 
filled with protoplasm and give rise to the dichotomously 
branching chains of carpospores. Usually three to five 
carpospores originate from each sporiferous branch by 
repeated abstriction of its terminal portion (Fig. 23 c). At 
first the carpospores are small, irregular in form (Fig. 2 6 c), 
