88 



AQ VATIC PHYCOMYCETES 



Fig. 6. Cytology of Cladochytrium replicatum and Endochytrium operculatum 



A-J. Cladochytrium replicatum Karling: A, zoospore, showing deep-stained 

 nuclear cap over anterior part of nucleus; at opposite pole of nucleus is a 

 small nucleole from which a delicate strand runs to point of attachment of 

 posterior flagellum; B, early stage in germination of an encysted spore lying 

 on surface of substratum; C, later stage in germination, showing nucleus 

 migrating into germ tube formed within substratum; D, pear-shaped primary 

 nucleus resting in first-formed spindle organ; E, two-celled spindle organ 

 from one cell of which a zoosporangium is developing; nucleus of zoospo- 

 rangium is in process of division; persistent nucleole lies within nuclear mem- 



