MORPHOLOGY S9 



particles are taken through a cytostome, as is the case with the 

 majority of euciliates, the food vacuoles are usually spherical and 

 of approximately the same size within a single protozoan. In the 

 saprozoic Protozoa, which absorb fluid substances through the body 

 surface, food vacuoles containing solid food, of course, do not occur. 



Chromatophores 



d 



Pvrenoids 



Fig. 32. a, Trachelomonas hispida, X530 (Doflein); b, c, living and 

 stained reproductive cells of Pleodorina illinoisensis, XlOOO (Merton); 

 d-f, terminal cells of Hydrurus foetidus, showing division of chromato- 

 phore and pyrenoid (Geitler); g-i, Chlamydomonas sp., showing the di- 

 vision of pyrenoid (Geitler). 



Chromatophore and associated organellae 



In the Phytomastigina and certain other forms which are green- 

 colored, one to many chromatophores (Fig. 32) containing chloro- 

 phyll occur in the cytoplasm. The chromatophores vary in form 

 among different species; namely, discoidal, ovoid, band-form, rod- 

 like, cup-like, fusiform, network or irregularly diffused. The color 

 of the chromatophore depends upon the amount and kinds of pig- 

 ment which envelops the underlying chlorophyll substance. Thus the 

 chromatophores of Chrysomonadina are brown or orange, as they 

 contain one or more accessory pigments, including phycochrysin, 

 and those of Cryptomonadina are of various types of brown with 



