456 
as supporting the opinion that “Die Blätter von Rh. 
subfusca stellen ein eigenartiges Mittelglied dar, über 
dessen Benennung man zweifelhaft sein kann” (I. c. 
p. 597). I cannot agree with the said author in this 
as there is only a slight gradual difference in the colour 
of the chromatophores in Rhodomela and in several 
species of Polysiphonia which have also rose-coloured 
chromatophores in spring and in deep localities. On 
the other hand the chromatophores of the trichoblasts 
in Rhodomela are often more or less decoloured during 
the spring, even in April." The trichoblasts begin to 
develop in winter (January) and are fully developed 
in spring (March to May). In June they are shed at 
the same time as the growth ceases, and in the follow- 
ing months no trichoblasts are met with except the 
uppermost ones which are apparently without function. 
Vigorous trichoblasts with red chromatophores have been 
met with only exceptionally in mid-summer, in the 
beginning of August in a specimen found in great depth 
in the North Sea (31 m), and in specimens of the f. 
Rhodomela nn ee tricho- tenuior found at Bornholm (8,5—15 m). 
blasts. a—c of var. virgata. 220: 1. As mentioned above, adventitious shoots may arise 
from superficial cortical cells of the stem in f. lycopo- 
dioides and other forms. The fasciculate branches occurring frequently in the long 
shoots of various forms of Rhodomela are probably. due to the production of such 
adventitious buds. 
The antheridia, as I have shown (1903 p. 462), arise on the stems and on the tricho- 
blasts (fig. 417). The fertile organs 
form corymbiform tufts at the ends 
of the shoots, or lateral on the 
long shoots in f. virgata. In some 
cases the fertile organs are appa- 
rently only branches, in others they 
are principally trichoblasts, but in 
both cases the main axis is usually 
covered with antheridia, and the 
formation of antheridia may extend 
to three generations of branches 
1 Further it must be remembered 
that the assimilating trichoblasts in 
Brongniartella are just as distinct from Fig. 419. 
the stem as those in Polysiphonia. Rhodomela subfusca f. virgata. Cystocarp. May. 95:1. 
