36 



MORPHOLOGY OF PROTOZOA 



structure and arrangement of the cilia on the body of ciliates and the 

 modifications undergone by those associated with the cytostome are 

 features of importance in the classification and determination of the 

 species and genera of the Ciliata, just as the number and characters of 

 the flagella are of importance in the classification of the Mastigophora. 



Amongst the Suctoria, which in their youngest stages are provided 

 with cilia, special organs for use in nutrition are developed in the adults 



Pid. 16. Monosiga coiisociatum from Hay Infusion ( x 2,000). (Original.) 



1-7. Free and attached individuals of varying size. 8 and 9. Encysted forms. 



CFW. 15). These are known as tentacles, and each is a tubular process 

 of cytoplasm terminating in a disc-like sucker. The latter is applied to 

 food material, which is taken into the body by a sucking process. It is the 

 possession of these sucking tentacles which has given rise to the names 

 Suctoria and Tentaculifera, by which these forms are known. 



Another type of structure which probably has to do with the capture 

 of food is the thin collar which is developed in certain Mastigophora 

 (Fig. 16). The cytoplasm at the anterior region of the body is raised 



