10G 



SEAWEEDS 



such longitudinal division as occurs in neighbouring 

 epidermal cells. The lower of the two cells again 



ft 



FIG. 27. a, Hydraclathru* cancellatux one-half natural size ; b, section of 

 thallus ; c, H. sinnomts, cryptostoma and paraphyses : d, mature cryptostoma 

 with young sporangia, b, c, 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 



