VEGETATIVE CHARACTERS. 



The thallus forms a hemispherical tuft, and is con- 

 posed of mizch "branched filsjiients, which are made up of large 

 swollen cells placed end to end in series. The filaments 

 radiate from a common point of at ta clime nt, the holdfast. In 

 a plant of average size, from the "base to the apeoc of a 

 single filaiaent, exclusive of the iDranches, there are twen- 

 ty to thirty cells; in large specimens the numter of cells 

 in a single filament may te tv;ice as great. 



The cells differ greatly in 3ha,pe and size in differ- 

 ent parts of the filaments (fig, 4). Toward the "base of 

 the plant they are approximately cylindrical below and much 

 swollen toward the upper end. The cells nearer the tip of 

 the filament become shorter and relatively thicker, of an 

 obovate shape, and of a deeper color. Those cells of the 

 female plant which bear the older cystocarps become very 

 much swollen toward t}ieir upper ends. In the male pla.nts 

 the terminal cells bearing the antheridia are almost glo- 

 bose. The following table gives a general idea of the 

 sizes of the various cells in a filajnent composed of 20 

 cells: 



