TO PROTOZOA. 157 



and Podophrya, (p. 51, fig. 25,) and so on to the highest of the 

 Protozoa. 



Having at last, then, passed the boundaries between vegetable 

 and animal life, and fairly stepped within the circle of sentient 

 beings, the next step that we would most naturally take is to 

 ascertain what are the relations which exist among them. 



