PROTOZOA. 161 



CHAPTER XI. 



PROTOZOA. 



Since all bioplasm possesses certain common characters, and the bio- 

 plasm of one plant or animal produces formed matter of a very different 

 kind from that resulting from another portion of bioplasm, we must ad- 

 mit that in nature there are different kinds of bioplasm. DR. BEALE'S 

 Bioplasm. 



I. IN studying the structure of the Protozoa, or primi- 

 tive animals, we seem to be going backward, since each 

 is composed of a single mass of bioplasm, like the sim- 

 plest vegetables, or Protophytes. Although similar in 

 structure, the Protozoa and the Protophytes are biolog- 

 ically distinct in function, since the latter generally de- 

 compose Carbonic acid under the influence of light, and 

 generate Chlorophyll and albuminous compounds in a 

 manner similar to the leaf-cells of the most perfect 

 plant, while the Protozoa ingest and digest both animal 

 and vegetable food as effectively as the most complex 

 animals. 



We have already seen (Chap. II, Sec. 7) that all living 

 matter, or bioplasm, has essentially spontaneous motion, 

 nutrition, growth, and reproduction. We cannot con- 

 ceive, therefore, of any form of life, either vegetable or 

 animal, without these characteristics. The simplest and 

 most embryonic structures in both kingdoms of nature 

 exhibit these functions. Whether spontaneous motion 

 is proof of consciousness and will, will be considered 



hereafter. 

 H* 



