Fertilization of the Floridez. 23 
bosum, Lyngb., &c.). In Griffithsia the penultimate joint- 
cell of a terminated small-celled branch-filament bears laterally 
two short two-celled branchlets, the lower cell of which produces 
lateraliy a four-celled carpogonial branch, and then itself 
becomes developed into the auxiliary cell. In Ceramium, on 
the other hand, the joint-cell of a still-growing branch develops 
laterally a two-celled branch, the lower cell of which becomes 
the rather large auxiliary cell, but also develops laterally not 
only one but two four-celled carpogonial branches. 
2. The arrangement of these parts in the multicellular off- 
shoots of the Rhodomelee is still more complicated and ditti- 
cult of recognition. 
In Polystphonia, as is well known, the individual joint-cell 
first of all develops a whorl of branch-cells, which, closing 
together firmly at the sides, surround the central cell with a 
closed rind, which, by the continued division and branching 
of its cells, becomes more or less thickened according to the 
species. Here the carpogonia are now usually formed on special, 
terminated, lateral offshoots. On one of the superior joint-cells 
of such an offshoot one of the “ marginal cells,” and indeed 
the last-formed unpaired marginal cell, grows into the four- or 
five-celled carpogonial branch. Its lowest cell becomes the 
auxiliary cell, but the small-celled apex of the branch bends 
upwards, so that the carpogonial cell touches the auxiliary 
cell with the lower angle (figs. 36, 28) ; while, in the simplest 
cases, from the auxiliary cell itself a unicellular, sterile, 
lateral branchlet proceeds downwards. At the same time the 
other “ marginal cells” of the above joint-cell divide and 
branch repeatedly, and thus produce a small cell-body, which 
encloses the carpogonial branch together with the auxiliary 
cell, and, as it rises as a whole distinctly on the thallus, may 
appropriately be characterized as a procarpium. 
In other species of Polysiphonia and other genera of the 
Rhodomelez this procarpium appears still more complicated, 
because, besides the terminal carpogonial branch, one or two 
lateral branchlets issue from the auxiliary cell, and these 
sometimes branch abundantly and give origin to a many-celled 
cell-complex, which in the fertilizable procarpia conceals the 
auxiliary cell, and may easily be interpreted (as, indeed, has 
hitherto been generally the case) as a ‘ group of carpogenous 
cells” (Chondria tenuissima, Ag.). Perhaps, also, in some 
of these forms a plurality of auxiliary cells may be formed in 
the individual procarpium ; but I have hitherto never been 
able to demonstrate such a case with certainty. 
3. Among the Chylocladiew the carpogonial branches in 
Chylocladia kaliformis, Hook., are usually very early formed 
