12 RHIZOPODA. 



resembling those represented in our engraving 

 (Fig. 2, 5), which must have lived for ages in some 

 quiet lake, whose waters covered the vast area where 

 they are found, and as they perished, sinking to the 

 bottom, left their shells records of their history. 



CHAPTER II. 

 BHIZOPODA* (Root-footed animalcules). 



To return to our magnified drop of water. We have 

 already described the Amoeba diffluens^ (Fig. 2, e), as 

 resembling a film of ever-changing cloud, so soft in its 

 consistence that it is but a little removed from fluidity. 

 It is not firm enough even to be called jelly : it may 

 almost be compared to a drop of gum- water or mucus, 

 and yet it is endowed with very extraordinary capa- 

 bilities. It evidently has a voluntary power of moving 

 from place to place, and its mode of doing so is not 

 inaptly expressed by the epithet " diffluens," flowing- 

 away, by which it is distinguished. On first perceiving 

 one of these creatures under the field of the micro- 

 scope, it will be found perhaps contracted into a 

 shapeless mass resembling a small patch of mucilage, 

 and offering little to attract attention; while we 

 watch it, however, it begins to move, spreads out 

 into a shape something like that represented in our 

 figure, and we are almost tempted to make a drawing 

 of so strange a creature. Meanwhile, it flows into 

 another outline, spreading like water spilled upon a 

 greasy board, and so it glides from place to place, 

 and form to form. This microscopic film is hungry too, 

 and eats ; but having neither mouth nor stomach, it 

 is not at first easy to conjecture how such a feat can 

 be accomplished. Its body is generally seen to con- 

 tain the shells of NaviculsB (Fig 4), and other similar 



* tfa, rhiza, a root ; irouy, TroSbs, pous, podos, a foot. 

 ^, amoibe, change. 



