CHAPTER II. 

 THE PEOTOZOA. 



Animals more or less resembling in structure the 



Amoeba {see p. 127). 



Classes. — Ehizopoda, or Amoeba-like animals. 

 IspusoMA, or Yorticella-like animals. 



The Peotozoa are minute animals which are either 

 unicellular or else composed of indefinite protoplasm, 

 not presentiug any division into cells. In the latter 

 case the organism may be either polynuclear or non- 

 nucleated. They reproduce themselves without form- 

 ing definite egg-cells and sperm-cells like those of 

 other animals. The Protozoa are all water animals 

 with the exception of some parasitic forms, and of one 

 or two kinds of Amoeba, which have been described as 

 living in damp sand. 



The chief divisions, or classes, of the Protozoa, are 

 the Ehizopoda, or root-footed animals, so called because 

 their most characteristic feature is, that they have 

 root-like processes or filaments of protoplasm (pseu- 

 dopodia), which help them to move and catch their 

 foodj and the Infusokta, originally so called because 

 they appear in abundance in infusions oi vegetable or 

 animal matter. 



The Rhizopoda include the orders Furaniinifera, 

 Heliozoa, and Badiolaria. The former have received 



their name from the fact that some of them have little 



i;!4 



