562 DESCRIPTION OF FIGURES. 



Kg. 



14. A green cell with red central substance, on the 

 point of assuming the motile form. 



15. An encysted zoospore, with filaments of proto- 

 plasm, (P. setter, Flotow), a distant " envelop- 

 ing cell," two cilia, chlorophyll-vesicles, &c. 



16. An encysted zoospore, with distant "enveloping 

 cell," green, gelatinous, primordial cell; red, 

 granular, disseminated central substance, and a 

 colourless point, (P. papillatus, Flot.) 



17. A very small, globular, encysted zoospore, (P. ro- 

 tundatus, Flotow.) 



18. An encysted zoospore, pointed at both ends, alto- 

 gether green, (P. rostellatus, Flot.) 



19. Commencing division of the primordial cell into two. 



20. A young pyriform primordial cell, around which 

 the " enveloping cell" is just beginning to show 

 itself distinct from the primordial cell. 



21. An older cell, with colourless vacuoles. 



22. Commencing division into two ; the wholly green, 

 primordial cell, closely surrounded by the en- 

 veloping cell, shows a constriction in the middle. 



23. Commencing division into two; each secondary 

 primordial cell has developed an enveloping cell 

 around itself, whilst still within the parent cell. 



24. Commencing division into four. 



25. An unusual and incomplete division into five; 

 four pointed, encysted zoospores, not completely 

 parted after the resorption of the common " en- 

 veloping cell," remaining connected by pro- 

 cesses arising from the point where the cilia are 

 placed ; a smaller portion has become organized 

 into a naked primordial cell, also connected with 

 the others. (Vide fig. 39.) 



26. Only half of the primordial cell consists of the 

 green globular substance; the other half is a 

 colourless granular protoplasm, enclosing in the 

 centre a red substance resembling a nucleus. 



27. An encysted zoospore in the commencement of 



