THE AMCEBA. 



13 



Observe : 1. A granular, translucent central portion (the 

 endosarc), with something of the appearance of ground 

 glass. 



2. A transparent outer border (the ectosarc), so clear it 

 is liable to be overlooked the first time an amoeba is seen, 

 and the endosarc taken for the whole animal. 



3. Irregular, blunt projections (pseudopodia, or false 

 feet), which are slowly pushed out from the body wall, or 

 drawn into it. Observe that in all of these there is the 



AMCEBA (X 500), drawn while moving in the direction of the arrow: 

 nu, nucleus ; v, vacuole ; ps, pseudopodia. 



same clear border and granular central portion ; and this 

 is true of their appearance when they protrude vertically, 

 as well as when extended laterally. If we can roll an 

 amceba over, we shall see the same arrangement of parts ; 

 so that we must conclude that the ectosarc forms a com- 

 plete outer layer about the whole animal. . 



Pseudopodia. Watch the formation of pseudopodia. 

 See first a protrusion of the clear ectosarc, then the flowing 

 of the more fluid granular endosarc out into it. * Observe 



