394 



CEdogoniales 



In the monoecious species of (Edogonium and Bulboch&te, and in the 

 dioecious macrandrous species of (Edogonium, the antheridium arises by a 

 division of a vegetative cell, in which the first dividing wall is laid down near 

 the apex of the cell. It is the upper small daughter-cell which becomes an 

 antheridial cell, and in some of the monoecious species it may remain the 

 only antheridial cell, thus constituting a unicellular antheridium. In most 



Fig. 248. Moncecious species of (Edogonium. 

 A, a form of (E. obsoletum Wittr. B, (E. 

 zig-zag Cleve var. robustum W. & G. S. West. 



C, (E. Itzigsohnii De Bary var. minor W. West. 



D, (E. Ahlstrandii Wittr. a, antheridium; 

 oo, oogonium. All x 460. 



Fig. 249. Dioecious macrandrous species of 

 (Edogonium. A , male plant of (E. rufescens 

 Wittr. ; B, female plant of same. C, female 

 plant of (E. lautumniarum Wittr. ; D, male 

 plant of same, a, antheridium ; oo, oogo- 

 nium. All x 460. 



cases, however, the antheridium consists of more than one cell, the antheridial 

 cells arising either by the continued division of the lower daughter-cell or by 

 division of the first-formed antheridial cell. 



The number of cells composing the antheridium is fairly constant for any one species, 

 and in the monoecious species the position of the antheridium relatively to the oogonium is 

 also a character of specific importance. 



