SECT. ii. RHIZOPODA. 1 3 



SECTION II. 



PROTOZOA. 



THE Protozoa are the very lowest forms of animal 

 existence, the beginning and dawn of living things. 

 They first appear as minute shapeless particles of semi- 

 fluid sarcode moving on the surface of the waters. 

 The pseudopodia, or false feet, with which they move, 

 are merely lobes of their own substance which they 

 project and retract. In creatures of a somewhat 

 higher grade the form is definite, the pseudopodia, 

 numerous and filamental, serving for locomotion and 

 catching prey; and from the resemblance they bear 

 to the slender roots of plants are called Ehizopods. 3 

 The microscopic organisms possessing these means of 

 locomotion and supply, are of incalculable multitudes, 

 and of innumerable forms. Thus the waters, as of old, 

 still ' bring forth abundantly the moving creature that 

 hath life ; ' in them the lowest types of the two great 

 kingdoms have their origin, yet they are diverse in the 

 manifestation of the living principle, that slender but 

 decided line which separates the vegetable from the 

 animal Amcsba. 



CLASS I. EHIZOPODA. 



The Amoeba, which is the simplest of the group, is 

 merely a mass of semi-fluid jelly, 'changing itself into 

 a greater variety of forms than the fabled Proteus, 

 laying hold of its food without members, swallowing 



3 From rkizon, a root, and ports, podos, a foot. 



