12 



SEX AND HEREDITY 



It is not quite so simple in structure as those before des- 

 cribed, for it consists of a number of encysted cells 



FIG. 6. 



Uluthrix zonata. A, young filament attached by rhizoid, ; ( 300) ; B, portion 

 of filament with escaping swarm-spores ; C = single swarm-spore ; D = formation 

 and escape of gametes ; E= gametes ; F, G = conjugation of gametes ; fl r = zygote; 

 / /y^otc alter period of rest; A" = zy;jote aftrr division into swarm-spores. 

 (After Dodel-Port. From Strasburger. B-K&4&2.) 



attached end to end, and sharing a common life. It is 

 thus a Plant with a multicellular body, which is fixed at 

 its base to the substratum (Fig. 6). In this state the 

 plant leads a vegetative existence, its cells nourishing 



