470 



Dansk Botanisk Arkiv, Bd. 3. Nr. 1. 



H. secunda as nothing else but two forms of the same plant. This 

 opinion I founded on the fact that the supposed difTerent ramifi- 

 cation, being the only real difference between them, would not be 

 proof against a thorough examination of more extensive material, 

 and this point of view, that the ramification in itself is not a suf- 

 ficient character of distinction, 1 still maintain, at any rate, to 

 a certain degree. 



Nevertheless, I have now come to the conclusion that we have 



to do with two different 

 species, my conclusion being 

 based on the fact that 1 

 have succeded in finding two 

 very different types of anthe- 

 ridial plants, so different 

 that they necessarily must 

 be regarded as belonging 

 to two distinct species. Had 

 these two difi"erent types 

 shown diverse forms of rami- 

 fication we might perhaps 

 by means of this have been 

 able to refer plants with 

 other fructiferous organs, 

 tetraspores and cystocarps 

 to their respective species. 

 But this was not the case, 

 both plants being ramified 

 with some differences in a 

 rather pecuhar way which 

 seems to be characteristic of the male plants. 



If we now leave out of consideration the ramification as a 

 character of distinction between the two species and look upon 

 the other differences between them mentioned in the descrip- 

 tions we find that the most essential one is that H. tenella is a 

 more slender plant than secunda. Taking this into consideration 

 I now refer the most robust form of the antheridial plants found 

 to Herposiphonia secunda^ the other to H. tenella^). 



1) The third West Indian form, H. Pecten-veneris (Harv.) Falkenb. is, 

 I think, nothing else but a form with recurved branchlets and summits 

 of branches. 



Fig. 428. Herposiphonia secunda (Ag.) 

 Falkenb. a, transverse section of anthe- 

 ridial stand, b, apex of branchlets with 

 antheridial stands in difTerent stages of 

 development, c part of a male plant. 

 (a, b, about 200:1; c about 50:1.) 



