563 ASA A. SCHAEFFER 



carmine grain only once. But in the five following trials with 

 the same carmine grain, there was not only no attempt at inges- 

 tion, but the positive reactions toward it gradually became 

 weaker. But when the behavior toward the second piece of car- 

 mine is considered it seems to be strikingly similar to the behavior 

 of the first ameba. On the first presentation the carmine was 

 promptly ingested. On the two subsequent trials, separated 

 from the first by two tests with cypris meat, the carmine was not 

 ingested, although positive reactions were observed. The third 

 carmine grain was again ingested. It is therefore quite evident 

 that some change was wrought in the carmine grain that passed 

 through the ameba. What the change was it is impossible to 

 say. But whatever the change, it is apparently not very marked, 

 or a given particle would not be eaten three times in succession. 

 On the other hand the change seems to be a definite and a con- 

 stant one and its effects on the later behavior of the ameba seem 

 to depend on the condition of the ameba, possibly on the degree 

 of hunger.' The first ame^ba, which ate each carmine particle 

 only once, may thus be regarded as having been in a state of 

 milder hunger than the second ameba, which ate one particle 

 three times in succession, but later, w^hen it may be supposed the 

 degree of hunger was less keen, a given particle was eaten only 

 once. All the particles that were eaten by this ameba were ex- 

 creted seven minutes after being eaten, excepting one — 282-283. 

 In this later case, in which the carmine was held for fourteen 

 minutes, there is a disturbing factor in that a flagellate was 

 ingested five minutes after the carmine was eaten. There can 

 be no question but that the carmine would have been egested 

 sooner if the flagellate had not been previously caught. It is 

 interesting to know that the ingesting process can arrest, for a 

 considerable time, the excreting process. 



The normality of the ameba is shown by the ingestion of the 

 flagellate. 



The long time during which the ameba rolled about the second 

 carmine grain, when first presented, is again not to be regarded as 

 an attempt to eat it, but as indicating a mild degree of hunger. 

 The ameba's state of hunger may have been rendered less keen 



