58 



Chlorophycece 



Most of the cells in Bulbochcete are furnished with long 

 tubular bristles and the terminal cell of the filament in one or 

 two species of CEdogonium also ends in a long bristle (fig. 14 C). 



There is one large chloroplast in each cell disposed in the 

 form of a cylindrical net-work, a large proportion of it forming 

 anastomosing cushions on the inner surface of the cell- WP 11. The 

 pyrenoids vary from one to several according to the species, and 

 sometimes the number varies in different cells of the same plant. 

 There is usually one nucleus with a prominent nucleolus (fig. 10 J n}, 

 situated in a more or less central position. The nucleus occasionally 

 divides without a corresponding division of the cell. Growth of 

 the filaments takes place by the transverse division of any of the 

 vegetative cells. 



Fig. 10. A I, (Edoponium sp., from Frizinghall, W. Yorkshire, showing stages of 

 one type of development from a zoogonidium in which the basal cell does not 

 become greatly swollen ( x 460). p, pyrenoid. J, (Edogonium sp., from Shipley 

 Glen, W. Yorkshire, after treatment with Acetic Acid and Hasmatoxyliu, show- 

 ing nuclei (n), x 460. 



