THE ALGAE 



135 



if 





B 



H 



Fig. 122. — Laminaria sacchorina. Gametophytic generation. A, Two-celled male thallus 

 showing on the left the empty wall of the zoospore and on the right antheridial branches. 

 B, Three-celled thallus with antheridial branches on right. C, First cell of female 

 thallus attached to empty wall of zoospore. D, One-celled female thallus with oogonium. 

 Oosphere emerging at top. E, Elongated oosphere. F, Antherozoids attached to the 

 protoplasm of the oosphere. G, Two-celled zygote. H, Primary filament of young 

 sporophyte. J, Older stage of young sporophyte showing apical growth. 



(From slides lent by Professor L. Newton.) 



