THE UHIZOPOD 9 



food; (4) chemical changes in the food take place: m other 

 words, n digests its food, i.e., s< parati cretee the por- 



tion necessary to nourish its body from those portions which 

 i8 wast : (5) it may also be said to breathe, the 

 changes involved in taking food, especially oxygen, caus- 

 the production and excretion of carbonic acid; (6) and 

 finally, it can reproduce it- kind. Tims we have foreshad- 

 owed in this exceedingly simple organism all the important 

 functions of animal life. 



t i.\--i - mi Protozoa. 



1. Body formless, usually shelled. RJti 



Body cylindrical; parasitic inula. 



3. Body ciliated Infusoria. 



Class I.— Rhizopoda (Root-animalcuh s). 



General Characters of Rhizopods. Besides the Ama 

 which is a representative vi this class, there are a numbei 





-' 



■ . ■ 



■ ■ 



l i.- L— A Foramlnlfer. Globigerina buUoides, magnified 70 di&mel 



oi fresh-water forms which have simple, silicious shells; 



but m the sea there are thousands of species whose -hells 

 are partitioned into chambers, and are usually perforated 



with holes like a sieve, through which the animal protrudes 

 its false feet or pseudopods. These shelled Rhizopods are 



