REACTIONS OF AMEBA TO PROTEINS 57 



This experiment is of interest in that it shows a gradual in- 

 crease in intensity of hunger (the quiet condition of the ameba 

 suggests the absence of hunger) until the side pseudopod came 

 into contact with the globulin; then a decrease in intensity of 

 hunger, leaving the ameba with even less intense hunger than 

 at the beginning of the experiment. A somewhat similar result 

 is observed in the following experiment, but infortunately only 

 the first part of the process, the increase in the intensity of 

 hunger, is recorded. 



In the experiment just alluded to (393) the ameba moved 

 gradually forward until the left hmb (399) came almost into con- 

 tact with the globuhn grain placed before the ameba, when it 

 was retracted and the ameba moved away. On the second trial 

 with the same piece of globulin (402) the ameba again broke up 

 into Y-form, the left pseudopod being directed toward the test 

 substance (404). When the left prong came into contact with 

 the globulin the right was retracted. The ameba then moved on 

 without further reaction. Note that in the first trial with this 

 ameba, the prong directed toward the globulin was retracted 

 while the other prong became the main pseudopod; while in the 

 second trial the reactions of the respective pseudopods were 

 reversed. This difference in behavior shows that the intensity of 

 hunger increased during the course of the experiment because of 

 the presence of the globulin. 



Similar to these two experiments is that recorded in figures 

 1616 to 1626. The ameba moved nearly into contact with the 

 globuhn (1619), then withdrew a short distance and threw out a 

 pseudopod on the right. From this side pseudopod another was 

 sent out which moved into contact with the globulin (1624), 

 But as soon as the pseudopod came into contact with the test 

 object, it was withdrawn and the ameba started to move away 

 to the right; but streaming was soon interrupted and directed 

 into the posterior end where a small pseudopod had been slowly 

 forming. The posterior end now became the anterior. There 

 can be little question that the ameba was not hungry and that 

 the presence of the globuhn heightened in this case the effect of 

 surfeit. The experiment is of interest because of the striking 



