Chapter 7 

 Phylum Protozoa Goldfuss 

 rriHE Protozoa are divided into two subphyla as follows: 



Locomotor organellae, pseudopodia or flagella, or lacking (in Sporo- 

 zoa); nucleus of one kind Subphylum 1 Plasmodroma 



Locomotor organellae, cilia or cirri; nuclei of two kinds 



Subphylum 2 Ciliophora (p. 481) 



Subphylum 1 Plasmodroma Doflein 

 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 pre- 

 vent a sharp distinction between the Protozoa and the Proto- 

 phyta, 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 

 Polymastigina may possess up to 8 or more flagella and of Hyper- 

 mastigina a greater number of flagella. The palmella stage (Fig. 84) 

 is common among the Phytomastigina and, unlike the encysted 

 stage, 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 com- 

 bination, are to be found among the members of Mastigophora. 

 In holophytic forms, the chlorophyll is contained in the chromato- 

 phores 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 chlorophyll 

 body (p. 79). Many forms adapt their mode of nutrition to 

 changed environmental conditions, for instance, from holophytic 

 to saprozoic in the absence of the sunlight. Holozoic, saprozoic 

 and holophytic nutrition are said to be combined in such a form 

 as Ochromonas. In association with chromatophores, there occurs 

 a refractile granule or body, the pyrenoid, which is connected 



171 



