214 . PROTISTS AND DISEASE 



the pylome three or four finger-like pseudopodia project. 



FIG. 60. ARCELLA VULGARIS. 1, Surface ; 2, Profile ; 6, Section of part 

 of shell ; 3, Binary division ; 4, (seen on the flat) Resting state, 

 trophonuclei, N ; and chromidium, Chr. ; 5, Formation of new nuclei 

 from chromidium. From various sources. 



In the vegetative phase, which is assumed in summer when 

 food abounds, the animal has two nuclei, each with a large 



