178 
or three on the same stalk (fig. 97). Some- 
times they appear to be produced directly 
from a cell of the vertical filament. 
The carpogonial branches are si- 
tuated laterally on the vertical filaments. 
They are somewhat variable in shape 
and number of cells. Usually they are 
two-celled, and the undermost cell then 
frequently projects considerably down- 
wards beyond the insertion point (fig. 99 A). 
SEES ETT] 
Fig. 96. 
Petrocelis Hennedyi,thin 
Sl 
Fig. 97. 
Petrocelis Hennedyi, from the 
. North Sea (Klitmøller), August. 
Vertical filaments with anthe- 
ridia. 390 :1. 
More rarely the carpogonial filament is 3-(or 4-)celled. A carpogo- 
crust from Lillebelt, nium situated directly on the vertical filament was also met with, 
March. Vertical fila- 
ments with truncate but the cell from which it was given off had in this case the 
end-cell. Sporangiasub- character of the cells of carpogonial branches (fig. 98 A), its con- 
terminal or terminal. 
390 : 1. tents being more homogenous and staining more intensely by 
Fig. 98. 
Petrocelis Hennedyi, from Bornholm, July. A, carpogonium situated directly on 
the vertical filament. B—D, two-celled carpogonial branches; in B and D the 
supporting cell has the same character as those of the carpogonial branch. E, 
carpogonial branch with short sporogenous filaments given off from the carpo- 
gonium and the subjacent cell. F, carpogonial branch producing (sporogenous ?) 
filaments. G, vertical filament with two larger cells, one of which bears a hyaline 
hair. H, vertical filament with a presumed auxiliary cell with scar after a decayed 
hair. J and K, auxiliary cells in contact with sporogenous filaments. L, probably 
young gonimoblast. A—E and L, 630:1 F—K 390:1. 
heematoxyline than the 
ordinary cells. This 
may also sometimes be 
the case with the cell 
bearing 2-celled carpo- 
gonial branches (fig. 
98 B). The cell bearing 
a carpogonial branch is 
frequently swollen, re- 
sembling the auxiliary 
cells. 
The auxiliary cells 
arise from single cells 
in the vertical filaments, 
which become some- 
what swollen and more 
susceptible to colouring 
matter. They appear 
to arise in some cases 
from cells having pro- 
duced a hair (fig. 98 
G, H). The develop- 
ment of the cystocarps 
has not been follow- 
ed; I have only obser- 
ved a few stages suc- 
ceeding the presumed 
