ON THE FEEDING HABITS OF AMEBA 565 



ward a short distance then sent out a pseudopod toward the 

 carmine. This pseudopod became the main one. The ameba 

 rolled the carmine about in all directions for twenty-two minutes, 

 at the end of which time it was in clavate form. The ameba 

 then speedily ingested the carmine in a large food cup with a 

 considerable amount of water. The ameba remained motion- 

 less for several minutes, then moved off 70° fo the left of the 

 direction in which the ameba moved previous to ingesting the 

 carmine. The final direction of movement was again the re- 

 sultant of the tendency to move forward in the original direction 

 and the tendency to move away from the carmine. About seven 

 minutes after ingesting it, the carmine was excreted. 



A piece of meat from the crustacean cypris was then laid twice 

 successively in the ameba's path, but only very mild positive 

 reactions were called forth — 246. 



The same piece of carmine used just previously was, for the 

 second time, laid near the ameba — 262. The ameba reacted defi- 

 nitely positively to the carmine, then moved on. When placed 

 near the ameba for the third time, a definite positive reaction 

 was again observed with a resultant change of direction of 

 motion. 



A fresh grain of carmine was then presented — 277. The ameba 

 flowed into contact with it and then ingested it in a typical food 

 cup with a considerable amount of water. Five minutes after 

 the carmine was ingested and after the ameba had begun to con- 

 tinue movement in the same direction, a flagellate became en- 

 tangled in some way on the upper surface of the ameba, causing 

 the formation of a food cup extending upwards in the water, in 

 which the flagellate was ingested. Three minutes after inges- 

 tion the flagellate ceased movement and at about the same time 

 the ameba moved off in the same direction in which it moved 

 while ingesting the carmine. The carmine was excreted fourteen 

 minutes after it was eaten. 



The most striking feature of the behavior of this ameba as 

 compared with that of the first ameba, is that at the beginning 

 of the experiment the same carmine grain was ingested three 

 times in rapid succession, while the first ameba ate any one 



