10 THE FORAMINIFERA 



there may be a denser covering or cortical layer, 

 derived from the same sarcode body. These inner 

 and outer portions may be termed respectively the 

 endoplasm and exoplasm. 



A good example of the protozoa may be seen in 

 the amoeba, which is common in pond water (fig, 8). 



Protozoa may, at one time of their existence, 

 form a coherent group or colony of cells. This, 

 however, is merely a case of cohesion or aggregation 

 after the increase of the original cell. 



Fig. 8. — Amleba proteus. x 500. Original. 

 N = nucleus, v = vacuole, F = foocl particles, c = crystalline bodies. 



With regard to the phenomena and ordinary 

 structures observed in protozoa we may notice the 

 following as of most importance : — 



The Nucleus. — This is a small more or less solid 

 body present in nearly all protozoan cells, having a 

 granular structure, and sometimes containing smaller 

 bodies of a like nature (nucleoli). It is capable of being 

 stained with various reagents, such as picrocarmine, 

 hsematoxylin, or methylene blue. For the reproduc- 



