20 BOTANICAL GAZETTE [JULY 

cell divides 1-3 times more, thus producing 3—5 layers of superficial — 
cells, the uppermost cell becomes the zoospore mother cell (fig. : 
20, b,c). Frequently several cell divisions take place in the super — 
ficial cell, so that a superficial cell develops into a filament consist- 
ing of more than 7 cells, the terminal one of which becomes the 
mother cell (fig. 21, a). Moreover, one of the superficial cellsj- 
unlike its neighboring cells, may develop into a long multicellular — 

—Sporelings from fertilized gamete 

Fic. 17, 
8: development in length is dominating. 
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€ sterile superficial cells 
The length of the mother — 

