ALG^E 



109 



Certain cells of the filament become very different from 

 the ordinary cells, enlarging and becoming globular (Fig. 

 99, A and B). In each one of these spherical cells there is 



FIG. 99.(Edogonium: A, portion of filament showing vegetative cell with its 

 nucleus (rf).an oogonium (a) filled by a large egg packed with food, a second 

 oogonium (c) containing an oospore, as shown by heavy wall, and two antheridia 

 (6), each containing two sperms; B, portion of filament showing antheridia (a), 

 from which two sperms (6) have escaped, a vegetative cell with its nucleus, and 

 an oogonium which a sperm has entered (c), and whose egg nucleus (d) may be 

 seen; C, swimming spore; D and E, young filaments developing from swimming 

 spores. 



