94 BOTANICAL GAZETTE [AUGUST 
naked protoplast discharged from the mother cell. I believe, how- 
ever, that this would be disproved by a careful reinvestigation. 
Formation of procarp 
Each disk cell produces one carpogonial branch or procarp. 
The steps in the development of the procarp are as follows: The 
disk cell divides to form two cells, the upper one becoming the 
auxiliary cell and the lower one the stalk cell. The auxiliary cell 
then gives rise to a cell at one side of its exposed terminal portion, 
and then similarly to another cell at the other side. Thus two 
sister cells are produced from the auxiliary cell, situated side by 
side. Of these two cells, the first one formed has become greatly 
elongated by the time the second sister cell is formed. The nucleus 
of the older sister cell divides to form two nuclei; one nucleus 
remains in the enlarged basal region of the cell (carpogonium) and 
becomes the carpogonial nucleus, while the other one enters the 
hairlike upper portion of the cell (trichogyne) and functions as the 
trichogyne nucleus. The trichogyne is separated from the carpo- 
gonium by a constriction. The younger sister cell, which is usually 
provided with one nucleus, ceases to grow further at an early stage 
in its development, and simply remains as a non-functional structure 
beside the carpogonium formed by its older sister cell. Every one 
of the many disk cells, at the growing tips of the thallus branches, 
produces a procarp. 
As just described, each procarp is composed of a stalk cell, auxil- 
iary cell, carpogonium, and trichogyne, together with the small non- 
functional sister cell of the carpogonium. The structure of the 
procarp of Corallina, therefore, would seem to be simpler than that 
of other Florideae; yet in many Florideae the procarps are solitary, 
or, as in the case of Ceramium, two occur side by side. In Coral- 
lina, however, 60-70 or sometimes over 100 independent procarps 
occur in a group within the same conceptacle, and after fertilization, 
before the formation of the carpospores, they fuse with one another, 
resulting in the formation of one common structure. 
Fertilization and formation of cystocarp 
The trichogynes project above the surface of the conceptacle 
and are thus freely exposed to the sea water. A floating sperma- 
tium comes in contact with the apex of the trichogyne, adheres to 
