364 Johnson. — On Stenogramme interrupta. 
fusion of the fertilised carpogonium and auxiliary cell, becomes 
the central cell of the cystocarp, increases in size, and sends off 
from its surface, more especially the under surface, numbers of 
radiating nucleated, septate meta-ooblastema filaments (Fig. 
12, a , b , c). The two or three carpogenous cells between the 
auxiliary cell and the carpogonium, which represent the 
‘ trichophore ’ of some writers, take no part in the formation 
of the cystocarps. To return to the consideration of the rest 
of the fertile line : — by the time the procarpia are quite ready 
for fertilisation the fertile line has become more conspicuous, 
partly owing to an increase in the number of superficial layers 
of cells, which layers of cortical cells ultimately form the 
general fruit-wall, partly owing to an increase in the size and 
richness of contents of the medullary cells of the line (Fig. 13). 
These accessory reproductive cells become more or less widely 
separated from one another, and though they, apparently, do 
not contribute directly to the formation of the carpospores, 
they must play a very important part in the supply of nutri- 
ment to the developing cystocarps. Before the procarpia are 
fertilised these medullary cells of the line are very full of food- 
materials : when the carpospores are just beginning to appear, 
their contents have become quite sparse. After the cystocarps 
have begun to form, delicate septate vegetative filaments make 
their appearance amongst the medullary cells; these branch and 
connect non-adjacent medullary cells with another. Similar 
filaments are to be observed in other Florideae, e. g. Crypto- 
nemiaceae, and are not to be mistaken for fertilising filaments. 
The nuclei of the meta-ooblastema filaments are derived 
from the central cell of the cystocarp. This central cell 
becomes multinucleate by the repeated divisions of the 
nucleus which results, judging by analogy, from the fusion 1 
of the nucleus of the fertilised carpogonium with the nucleus 
of the auxiliary cell. As the septate meta-ooblastema 
filaments increase in importance, the rich medullary cells part 
with most of their contents to the developing cystocarps, and 
1 I saw many cases of fusion of these two cells, sometimes several cases in the 
same section, but was not fortunate enough to see their nuclei fusing. 
