ON THE FEEDING HABITS OF AMEBA 563 



once as near the posterior edge as possible. The reaction of the 

 endoplasm toward carmine is therefore different from that of the 

 ectoplasm. 



Those cases where the ameba rolled the carmine grain along in 

 various directions in front of it, cannot be described as attempts 

 to ingest the grain in view of the fact that all the grains of car- 

 mine which were swallowed at all, were swallowed at once with- 

 out rolling them. We shall meet with a number of instances of 

 the same sort in the following experiments. The cause of such 

 behavior may now be labeled as a mild state of hunger, a little 

 too strong to leave the test object alone and too mild to produce 

 ingestion. It is not due to a partially or wholly unsuccessful 

 attempt at ingestion as Jennings ('04, p. 196) has suggested. 



For the sake of comparison the behavior of an ameba from 

 another dish toward carmine may now be taken up. The ex- 

 ternal appearance of this ameba was similar in all respects to the 

 preceding one. Both the cultures from which these amebas were 

 taken were inoculated at the same time with material taken from 

 the same pond. The ameba belonged to the granular type. 



A grain of carmine of grade 2 was laid near the main pseudopod 

 of the ameba — -153. The ameba moved into contact with it, then 

 formed a large food cup with the carmine at its mouth. The 

 carmine was finally complete^- enclosed and the ameba quieted 

 down for about two minutes. A pseudopod was then thrown 

 out 90° to the right of the ameba's original direction of movement. 

 Through this pseudopod the ameba moved away. The carmine 

 was excreted seven minutes after it was ingested. The direc- 

 tion in which the ameba moved away was the resultant of the 

 tendency to move straight forward and the tendency to move 

 directly away from the carmine, both tendencies being of about 

 equal strength. 



Five minutes later the carmine grain was placed to the left of 

 the ameba — 163. (A very small fragment broke off in shifting it.) 

 It happened that a side pseudopod came nearer the carmine than 

 did the main one, and the ameba then flowed into the side pseudo- 

 pod while the main one was retracted. • The carmine grain was 

 rolled to the right slightly when another pseudopod was thrown 



