CHAPTEK lY. 



WHAT IS EOZOON ? 



The shortest answer to tlus qwestiort is,, that this ancient 

 fossil is the skeleton of a creature belonging to that 

 simple and humbly organized group of animals which 

 are known by the name Protozoa. If we take as a 

 familiar example of thesathe gelatinous and microscopic 

 creature found in stagnant ponds_, and known as the 

 Amoeha^ (fig. 12), it will form a convenient starting 

 point. Viewed under a low power, it appears as a 

 little patch of jelly, irregular in form-, and constantly 

 changing its aspect as it moves, by the extension of 

 parts of its body into finger-like processes or pseudo- 

 pods which serve as extempore limbs. When moving 

 on the surface of a slip of glass mider the microscope, 

 it seems, as it were, to flow along rather than creep, 

 and its body appears to be of a semi-fluid consistency. 

 It may be taken as an example of the least complex 

 forms of animal life known to us, and is often spoken 

 of by naturalists as if it were merely a little particle 

 of living and scarcely organized jelly or protoplasm. 

 When minutely examined, however, it will not be found 

 so simple as it at first sight appears » Its outer layer 

 * The alternating animal,, alluding to its change of form. 



