in Gracilaria confervoides , Grev, 2 1 9 
the procarpium (c. Fig. 1, c.c. Fig. 2) has grown out as the 
trichogyne across the fruit-cavity, and through the fruit-sheath, 
between its cells, to the external surface, only the most internal 
part of the pore being present when this occurs. Fertilisation 
now takes place. This act is followed by the fusion of the fer- 
tilised ovicell with the rest of the procarpial cells, the tricho- 
gyne being cut off in the usual way. The compound 
procarpial cell now enters into communication, by the for- 
mation of protoplasmic diverticula through its now swollen 
wall, with the immediately adjacent cells of the placenta. At 
the same time it develops at its free apex independent proto- 
plasmic protrusions. Spores now appear with or without pre- 
vious repeated division of the placental cells ; the pore is fully 
formed ; and the fruit-cavity enlarges at the expense of the 
innermost cellular layers of the fruit-sheath. 
I must confess inability to explain the formation of the swel- 
ling by periclinal division in harmony with the theory of F. 
Schmitz 1 , who regards all parts of the thallus of Florideae as 
composed of systems of branching filaments of cells. Possibly 
the swelling, a unique structure in the Florideae, is one of the 
few exceptions it is admitted may occur. The time of origin 
of the different parts of the procarpium in Gracilaria agrees 
with the time assigned by Schmitz as that at which the pro- 
carpium in Florideae generally developes. Following out his 
explanation and terminology, it may be said that in Gracilaria 
(Fig. 1) a joint-cell,/ 1 , produces near its apex, on one side, a 
two- or three-celled carpogenous branch,/ 2 ,/ 3 , c, the apical 
cell of which, c, becomes the carpogonium (carpogenous cell), 
and gives origin to the trichogyne ; on the other side, a two- 
celled branch,/ 4 ,/ 5 . After fertilisation the basal part of the 
carpogonium is cut off as the fertilised ovicell, and combines 
with the auxiliary cells,/,/ 1 ,/ 2 ,/ 3 ,/ 4 ,/ 5 , to form one large 
copulation-cell, which further combines, in the manner pre- 
viously described, with the surrounding placental cells — ■ 
1 F. Schmitz, Untersuchnngen iiber die Befrachtnng der Florideen, in Sitzungsber. 
d. k. Akad. d. Wiss. Berlin, 1883. A translation of this paper by W. S. Dallas, 
F.L.S., appeared in Ann. Mag. Nat. Hist. vol. xiii (1884). 
R 
