F. Børgesen: Rhodophyceæ of the Danish W. Indies. 



211 



the plant, in others this is not the case as several branches are 

 nearly equally vigorous. 



No cortical layer is found, but from the basal cells of the 

 more vigorous branches a rhizoid-like filament often emerges (Fig. 

 194 d), growing downwards along the main stem, but generally 

 not attached to it. In the lowermost part of the plant, as 

 mentioned above, these rhizoids reach down to the host plant 

 and fasten themselves to it, but higher up it may happen that 

 they attach themselves to a branch beneath them. 



Fig. 196. Mesothamnion caribaeum nov. spec, a, part of an antheridial 



plant, b, antherial stands, c — h, development of antheridial stand. 



(a, about 50:1; b, about 125:1; c—g, about 300:1; h, about 450:1). 



The plant is much ramified (Fig. 195), the branches issuing 

 multilaterally to all sides. As mentioned above some of the 

 branches grow out vigorously like the main stem, but most of 

 them are not so much developed. These smaller branches are in 

 the same way multilaterally ramified, bearing repeatedly pseudo- 

 dichotomously ramified branch].ets on all sides. The branchlets 

 are longest at the base of the branches, higher up shorter and 

 at the same time bent upwards, the whole branch in this way 



14* 



