DYSENTERY. 



365 



lost in a state of rest. Frequently, foreign bodies, especi- 

 ally red blood-corpuscles, also bacteria, much less com- 

 monly leukocytes, may be seen within the entoplasm ; at 

 times the protoplasmic body is literally stuffed with blood- 

 discs. The ameba invariably contains a nucleus, which, 

 however, is not always clearly visible in the moving cells. 

 The nucleus is usually eccentric, and with change in shape, 

 often near the periphery. It has a diameter of between 6 

 and 8 p., is round in shape, generally with a sharp contour, 

 and a punctate nucleolus. At times the contents of the 

 nucleus are slightly granular. 



The characteristic of the ameba is its mode of movement, 

 which is designated ameboid. The ectoplasm is extended at 



Fig. 83. Amoebae coli in intestinal mucus (after Losch). 



any given point in the form of a blunt, roundish, homo- 

 geneous process, and the protoplasm flows after it. In 

 this way an actual change in position can be brought 'about 

 by a slow, at times backward, crawling movement. The 

 process may further be retracted, to appear immediately at 

 the same or at another point! The ameba is thus engaged 

 in constant change in shape. At. times the ectoplasmic 

 processes move around the central mass in waves without 

 locomotion taking place. 



Little is known regarding the nutrition of the amebae. In 

 general the foreign bodies so frequently seen in the ento- 

 plasm, especially the red blood-corpuscles, are considered 

 as nutrient material. These are taken up by a process of 



