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Chapter 8 

 Phylum Protozoa Goldfuss 



Subphylum 1 Plasmodroma Doflein 



HE Plasmodroma possess pseudopodia which are used for loco- 

 motion and food-getting or flagella that serve for cell-organs of 

 locomotion. In Sporozoa, the adult stage does not possess any cell- 

 organs of locomotion. The body structure is less complicated than 

 that of Ciliophora. In some groups, are found various endo- and 

 exo-skeletons. The nucleus is of one kind, but may vary in number. 

 Nutrition is holozoic, holophytic, or saprozoic. Sexual reproduction 

 is exclusively by sexual fusion ; asexual reproduction is by binary or 

 multiple fission or budding. The majority are free-living, but numer- 

 ous parasitic forms occur, Sporozoa being all parasitic. 



The Plasmodroma are subdivided into three classes as follows: 



Trophozoite with flagellum Class 1 Mastigophora 



Trophozoite with pseudopodium Class 2 Sarcodina (p. 328) 



Without cell-organs of locomotion; producing spores; all parasitic 



Class 3 Sporozoa (p. 427) 



Class 1 Mastigophora Diesing 



The Mastigophora includes those Protozoa which possess one to 

 several flagella. Aside from this common characteristic, this class 

 makes a very heterogeneous assemblage and seems to prevent a 

 sharp distinction between the Protozoa and the Protophyta, as it 

 includes Phytomastigina which are often dealt with by botanists. 



In the majority of Mastigophora, each individual possesses 1-4 

 flagella during the vegetative stage, although species of Polymasti- 

 gina may possess up to 8 or more flagella and of Hypermastigina a 

 greater number of flagella. The palmella stage (Fig. 88) is common 

 among the Phytomastigina and the organism is capable in this stage 

 not only of metabolic activity and growth, but also of reproduction. 

 In this respect, this group shows also a close relationship to algae. 



All three types of nutrition, carried on separately or in combina- 

 tion, are to be found among the members of Mastigophora. In holo- 

 phytic forms, the chlorophyll is contained in the chromatophores 

 which are of various forms among different species and which differ 

 in colors, from green to red. The difference in color appears to be due 

 to the pigments which envelop the chlorophyfl body (p. 78). Many 

 forms adapt their mode of nutrition to changed environmental con- 



198 



