ONE-CELLED ANIMALS— PHYLUM PROTOZOA 



93 



Protozoa with Flagella — The Mastigophora 



The members of this class have a more definite shape than the Sarcodina 

 and are characterized by the presence of a whip-like attachment known as 

 a flagellum. The flagellum is used in swimming — some genera, like 

 Euglena, use it to pull themselves through the water, beating it down to 



Flagellum 



Eye spot 



Reservoir 



Contractile 

 vacuole 



Nucleus 



Chloroplast 



Pellicle 



Fig. 7.5. Euglena viridis. This unusual organism has both plant-like and animal- 

 like characteristics. 



their sides as they go ; while others, like Trypanosoma, use it as a tail to 

 push themselves along. 



A typical example of this class is Euglena viridis. When you look at 

 one of these under the microscope you may be surprised to find that this 

 animal contains chlorophyll within chloroplasts. This green substance 

 is usually found only in plants, and for this reason euglena is sometimes 



