Fertilization of the Floridez. 15 
In these forms the fertilized ovicell usually develops only a 
single ooblastema-filament (Caulacanthus, fig. 39, Pterocladia), 
which, ramifying abundantly, turns towards the middle of the 
branch of the thallus to which it belongs, and with its rami- 
fications clings round the central cord of cells, the so-called 
central axis of the branch, which at this part is frequently 
(Pterocladia, Wrangelia pectinata, Ag.) enveloped by a 
special small-celled tissue with abundant contents. Through 
the cell-masses of this tissue the ramifications of the ooblas- 
tema-filament twist about and frequently attach themselves 
firmly to individual very full cells of this tissue (Pterocladia), 
or, when it is deficient, to the cells of the central cord itself 
(Caulacanthus, fig. 39), here and there also entering into 
direct connexion with them by the development of pits 
(Wrangelia). Bemg abundantly nourished through the 
agency of this tissue, the branches of the ooblastema-tilament 
then ramify very considerably, and develop from each of the 
clavate and erected terminal branch-cells either a single spore 
(Caulacanthus) or short chains of two (or more) spores, in the 
same way as in the Helminthocladiez already described. 
Thus by the abundant ramification of the ooblostema- 
filament there is produced a tuft of spore-forming filaments, 
which spread out in the interior of the branch of the thallus, 
and give rise to a local enlargement of it. This enlargement 
increases more and more until the maturity of the spores, 
and becomes constantly more and more distinctly marked off 
from the remaining sterile part of the thallus-branch. This 
dilated part then finally constitutes the fruit, the cystocarp, of 
these Floridean genera, the peripheral tissue of the thallus 
becoming developed into the fruit-wall, in which an aperture 
of egress is produced by local separation of the cells, while in 
the interior the mass of the spores is produced around the 
central cell-cord from the ramifications of the ooblastema- 
filament. : 
In some of these forms (Naccaria Wigghit, Endl., and 
hypnoides, J. Ag.) a further complication of the course of 
development of the fruit occurs. Here the carpogonial branch 
in very different states of development is beset with several 
short lateral branchlets, and in this way forms a pluricellular 
complex of larger and smaller cells (figs. 24 and 26 *), gene- 
rally with abundant contents. ‘The sprouting ovicell now 
enters into open connexion with one or another of these 
neighbouring larger cells, with complete amalgamation of the 
two plasma-bodies (fig. 27), and only then does the ooblastema- 
* See the explanation of the figures. 
