452 
the fructification, while the corresponding branchlets in Rh. subfusca after fructific- 
ation may develop as vegetative shoots, and the fructification in this species takes 
place later, in spring. KJELLMAN also found anatomical differences between the two 
species, the cells in the main axes of Rh. virgata decreasing gradually in size towards 
the periphery, while Rh. subfusca has a small-celled cortex rich in “endochrome”, 
distinctly bounded towards the inner parenchyma consisting of large cells. Rh. lyco- 
podioides is considered as a distinct species though nearly related to Rh. subfusca. 
Kjellman emphasises as distinctive characters the numerous curved branchlets hay- 
ing their greatest thickness a little 
below the middle; they are arranged 
without any distinct order and are 
supposed to be adventitious. 
While REINKE and FALKENBERG 
do not adopt Rh. virgata as a distinct 
species, KyLın follows KJELLMAN, 
laying particular stress on the 
different season of fructification 
(Nov. to Jan. for Rh. virgata, April 
and May for Rh. subfusca) and on 
Fig. 411. the fact that the new shoots which 
Rhodomela subfusca. A (f. virgata) adventitious shoots near the in Rh. subfusca develop in the last 
base of a primary branch. 64:1. B transverse section of stem à 3 2 
with a young adventitious shoot. 206 : 1. part of the winter and in spring, 
are at first both vegetative and fertile 
but after fructification remain as vegetative, while the organs of reproduction in Rh. 
virgala are seated in particular shoots which are thrown off after fructification. 
As to the branchlets of Rh. lycopodioides 1 have convinced myself, by examin- 
ation of specimens from Iceland and Greenland, that numerous adventitious branch- 
lets really occur in this species, arising from a single superficial cell growing out 
and dividing by a transversal wall, whereupon the outer cell becomes the apical 
cell of a branchlet. A similar formation of adventitious shoots has not only been 
met with in specimens from the Danish coasts otherwise fairly agreeing with Rh. 
lycopodioides, but also in specimens of Rh. subfusca and Rh. virgata (figs. 411 A). In 
the latter they were produced in particular near the base of the primary shoots. 
The occurrence of adventitious branchlets has thus no absolute value as distinctive 
character, and the same is, according to my experience, the case with the alleged 
shape of the branchlet and other characters, and I must therefore agree with the 
authors who have more or less distinctly suggested that Rh. lycopodioides might be 
considered a form of Rh. subfusca. 
As to the two species Rh. subfusca and Rh. virgata as distinguished by KJELL- 
MAN, to which most of the Danish species can be referred, it must be confessed, 
that in their typical shape they are so distinct as to habit and anatomical structure 
that they have the appearance of being distinct species. The examination of a great 
