106 SEAWEEDS 
such longitudinal division as occurs in neighbouring 
epidermal cells. The lower of the two cells again 
Fic. 27.—a, Hydroclathrue cancellatus one-half natural size ; b, section of 
thallus ; ¢, H. sinuoaus, eryptostoma and paraphyses ; d, mature eryptostoma 
with young sporangia. b, ¢, d highly magnified. (After M. O. Mitchell, in 
Phyc. Mem.) 
divides transversely, and this method of division 
continues till a long row of cells has been formed, 
making in fact a hair, Simultaneously with the 
