12 



M. Tahaw. 



Fig. 4. X140 



state which is never found in Sargassum. 

 The rhizoid cells elongate to form a numebr 

 of rhizoids; similar to what has been 

 described in the case of Sargassum, the 

 rhizoids originating from the central region 

 grow more rapidly than those originating 

 from the outer region (Fig. 8, PL. III). 

 But in this case the central group of 

 rhizoids are also derived from the rhizoid 

 cell formed by the second segmentation 

 wall, although in later development there 

 may be some rhizoids derived from body 

 cells as in Sargassum. 



^t\ 



\ 



\ 



Wß 



V 



Fig. 5. X 175 



As already stated, the early development of sporelings, both 

 in Sargassum and CijstophyUum^ is carried out while they are 

 enveloped in the oogonium wall. But in the course of develop- 



