THE ALGAE 



J33 



The Gametophytes 



The result of germination is the formation of very small male and female 

 gametophytic plants, both of which are filamentous and differ completely 



Fig. 1 20. — Lafnitian'a sp. Longitudinal section through part of 

 the medulla of the stipe showing trumpet hyphae and 

 septate transverse filaments. On the right a single trumpet 

 hypha showing sieve-like perforation of the seed plate. 



from the sporophytic thallus. They also differ from each other in shape and 

 size. 



On germination the zoospore first forms a tube which terminates in an 



Paraphyses 



Zoosporangium 



Fig. 121. — Laminaria digitata. Zoosporangia on surface of the thallus. 



