74 



ELEMENTARY ZOOLOGY. 



of producing a denser outer portion the cell wall (Figs. 

 2 and 3, w). This protoplasm has all the powers men- 

 tioned in the preceding section in their very simplest 

 form. The one-celled animals are very varied in shape 



FIG. 7. Various single-celled animals. 1-4, Rhizopoda; 5, Sporozoa (stages of 

 parasite of malaria); 6-9 free-swimming ciliate Infusoria; io,a ciliate stalked infusorian; 

 ii, a stalked flagellate infusorian; 12, a free-swimming flagellate form. 



Questions on the Figure. What degree of differentiation can you 

 find among these animals? What suggests that they are animals 

 rather than plants? Compare them in order to give statement to 

 the differences between them in structure; in possible activities 

 as motion, taking of food, and the like. By reference to figures of 

 other texts determine what species these are most like. 



and size., but they are very uniform in the fundamental 

 work which they must do. A page of such animals will 

 be seen in Fig. 7. 



In the very nature of the case there can be no complex 



