AMGEB^E OF THE INTESTINAL TRACT. 129 



membered that in the Entamoeba coll the pseudopodia 

 are short and blunt, but in this species they are 

 generally finger-like in shape and of large size. 



Three forms of motility may be distinguished: 

 active progressive motion, the extrusion of pseudo- 

 podia without progression, and movements of the 

 cytoplasm. 



The character of the progressive motion in freshly 

 passed feces varies considerably, but it is generally 

 rapid when compared to the sluggish motion of Enta- 

 moeba coli. As the feces become cool progressive 

 motion is gradually lost and, in such specimens, may 

 be entirely absent or so sluggish as to require careful 

 and prolonged observation to distinguish it. The 

 organism advances by throwing out clear pseudopodia 

 into which the endoplasm flows. The shape of the 

 pseudopodia varies from a round, broad mass of 

 ectoplasm to long slender processes with rounded 

 extremities. Pointed pseudopodia so frequently ob- 

 served in free-living species of amoeba* are never 

 observed in any of the parasitic species of man. The 

 long, slender pseudopodia are most frequently ob- 

 served in the rapidly moving organisms, the more 

 rounded pseudopodia occurring in amrebae possessing 

 sluggish motion. 



The pseudopodia are always hyaline in appearance 

 when first extruded, but the endoplasm quickly flows 



