472 



mentarily developed; and the branchlets are developed in a very 

 restricted number. 



The most common form of ramification found in the male 

 plant is that drawn in the diagram (Fig. 429) and also clearly 

 seen in the Fig. 428 c namely, after a segment with a branchlet 

 issuing, as it seems, from the dorsal median line, follows one with 

 a rudimentary branch alternately on the right or left side of the 

 stem, but always on the opposite side of the stem as the fore- 

 going, then three bare 

 segments, then one 

 with a branchlet and 

 one with a branch 

 and so on. In another 

 specimen in which 



no branches at all 



"V ' 



\ 



Fig. 429. Scheme of the ramification as found in 

 the male plants of Herposiphonia secunda (upper- 

 most) and in Herposiphonia tenella (lowermost). 

 (The apical end at the left). 



were developed I 

 found generally three 

 bare segments be- 

 tween each with a 

 branchlet, once only two bare segments. The branchlets seem 

 all to be issued from the dorsal median line of the main branch, 

 not being arranged in zig-zag form as is commonly the case. 



This varying arrangement of branchlets and branches, differ- 

 ing much from that commonly found in Herposiphonia, seems to 

 support my view that no systematic value can be attached to it. 

 So far I have seen, both the main filaments and branchlets 

 of this form have eight pericentral cells. The branchlets are about 

 80 p thick. 



Of the forms mentioned in my description on p. 286 I now 

 think it best to refer the plants figured in Figs. 288 and 289 to 

 H. secunda, these having short segments and being on the whole 

 rather robust. 



135. Herposiphonia tenella (C. Ag.) Nagl. 



The male specimens referred to this plant have more slender 

 antheridial stands than those of H. secunda (Fig. 430). Commonly 

 the whole stand together with basal cells and apex reaches a length 

 of about 150 p (the fructiferous part alone 125 p) and a breadth 

 of about 40/^; the largest antheridial stand found on the whole 

 was 240 p long and 55 p broad. 



