Dar bishire. — On A ctinococcus and Phyllophora. 257 
time that the antheridial cavities of Phyll. Brodiaei often 
accompanied the presence of Actinococcus subcut aneus, but 
only during the last year has it become possible to explain 
definitely the significance of this appearance. 
As the presence of the antheridial cavities is so inti- 
mately associated with the relationship of the two red Algae 
which form the subject of 
this paper, it might be use- 
ful to recall the structure 
of the former (2, p. 29). 
The antheridia of Phyll. 
Brodiaei are developed in 
the cortical layer of the 
spermophores, the latter 
being shoots more or less 
modified temporarily for 
the production of the male 
organs (Figs. 4, 5). They 
are slightly flattened near 
the lighter coloured apex, 
attaining a length of about 
3 mm., being rarely broader 
than 0-5 mm., and they are 
borne on the apical margin 
of the flattened vegetative 
thallus. In the cortex 
of such a spermophore, 
close to its apex and not 
further down from it than 
1 -0-1-5 mm., we find the 
small cavities which con- 
tain the antheridia. These 
cavities are flask-shaped and communicate with the ex- 
terior by a small ostiole. Their height is 24-34 /x, their 
breadth about 20 /x. From the flat bottom of the flask- 
shaped cavity arise a number of 2, 3 or even 4-celled 
antheridia, which produce the single male cells or spermatia, 
Fig. 4. Phyllophora Brodiaei (Turn.) 
J. Ag. I. Two spermophores. x iodiam. 
II. Longitudinal section of spermophore, 
showing the antheridial cavities in the 
cortical layer, x 200 diam. 
