THE PROTOZOA OR THE SIMPLEST ANIMALS 



mouth. Near the base of the flagellum is a small eye- 

 spot. In the endoplasm there are numerous bodies con- 

 taining chlorophyll, a compound which enables the green 

 plants to utilize carbon dioxide in building up their living 

 substance. Euglenas exposed to light take in C02 and 

 give off 0, just as the higher plants do. At the same time 

 they swim about like animals and are said to take in a 

 small amount of solid food through the mouth. Like 

 Paramcecium, Euglena multiplies by fission, but it divides 



FIG. 118. A, Vorticella; c, cilia; cv, contractile vacuole; fv, food 

 vacuole; g, gullet; n, nucleus; 5, contractile stalk; v, cyst of Vorticella; 

 B, a flagellate Euglena viridis. cv, contractile vacuoles; e, eye spot; m, 

 mouth; n, nucleus. 



longitudinally as do most other flagellates, instead of trans- 

 versely. At times it may go into an encysted state in 

 which it sometimes divides into two or more individuals. 

 Some flagellates are more completely plant-like than 

 Euglena, while there are others which are more like typical 

 animals. In fact the animal and plant kingdoms seem to 

 draw together in the flagellates which form a sort of 



common base from which they both diverge. The plant- 

 10 



