Ainoehaea.] THE INFUSORIA. 165 



Family VIII.— AMOEBAEA. 



The infusorial animalcules of this family are poly- 

 gastric, with one aperture only to the body, and no 

 alimentary canal or lorica. No other organs of motion 

 are observable than certain appendages or ramifications, 

 consisting of variable pediform processes, which they have 

 the power of putting forth from every part of their 

 gelatinous and contractile bodies, and by which they move 

 from place to place. The organs of nutrition are com- 

 posed of numerous digestive cells, which are visible in 

 all the species, either in their natural state, or by the 

 introduction of coloured substances into them. Self- 

 division has been seen in Amoeba diffluens. No indica- 

 tions of a sensitive system are discoverable in any species. 

 As only one genus is known in this family, it is exempU- 

 fied by the family characteristics. 



Genus XL. Amoeba. 



148. Amoeba princeps (Proteus diff. M.) The great 

 Amoeba. — Body of a pale yellow colour, furnished with 

 numerous variable processes, somewhat cylindrical in 

 form, with the terminations thick and rounded. This 

 curious creature, from its slow motion and yellowish 

 colour, is a desirable object for the microscope ; its sin- 

 gular changes of form, and its internal organization, may 

 be viewed with considerable pleasure, even under very 

 high magnifying powers. Its normal shape, if such it can 

 be said to possess, is globular, but it can relax any portion 

 of its body, and contract the rest, so as to force the 

 internal part down into this relaxed portion, in a manner 



