132 
Entamoeba histolytica 
PSEUDOPODIA. 
The pseudopodia are blunt. When they begin to protrude, they are 
ectoplastic. Soon, however, the granular endoplasm flows into them; in this 
flowing movement there is a central stream of protoplasm, which bends 
round in all directions “fountain fashion,” as soon as the periphery of the 
pseudopodium is reached. While this is taking place at the end opposite 
the pseudopodium, the endoplasm passes forward so that a slight progression 
of the whole animal occurs. At times, however, there is no translatory move¬ 
ment, although active pseudopodial formation is taking place. The text- 
figure below represents the movements of a culture form observed on the 
warm stage of the microscope. The pseudopodia were formed very rapidly, 
but from 3-30 to 3-35 there was no forward movement of the animal. This 
sudden development of pseudopodia from all parts of the body, unaccompanied 
Fig. 1. Successive drawings made of the pseudopodial formation in a culture amoeba 
containing a blood corpuscle and many bacteria. 
by progression, is a very characteristic feature of E. histolytica , as distinct from 
E. coli. 
In stained preparations the pseudopodia are seen to be composed inter¬ 
nally of a mesh work of protoplasm, which has apparently streamed out fiom 
the endoplasm as in the living organism, Plate VII, fig. 4. 
FOOD INGESTION AND DIGESTION. 
In the endoplasm of the amoebae a large number of blood corpuscles 
and other food particles are usually seen. Occasionally I have observed the 
method of ingestion of the blood corpuscles, which has always been that 
designated by Rhumbler (1910) as invagination. The amoeba on touching 
the object to be engulfed adheres to it, the part of the ectoplasm in contact 
with the food is invaginated into the endoplasm, forming a tube-like structure 
