548 ASA A. SCHAEFFER 



of the series moderate quantities of water are taken in with the 

 food object and the protoplasm flows around it a at greater dis- 

 tance and touches it at perhaps only one or two points. Those 

 cases which come at the end of the series where the formation 

 of food cups finds its highest expression, are characterized by the 

 taking in of a very large quantity of water with the food, and the 

 almost complete formation of the food cup before the particle of 

 food is touched. Now the same object may cause feeding reac- 

 tions falling anywhere in the series as above described. A food 

 cup msiy be formed touching the object at many points and con- 

 taining a minimal quantity of water; or a food cup may be formed 

 at a considerable distance from the object and containing a large 

 amount of water. These differences in the size of food cups as 

 compared with the size of the object are not always referable to 

 the object around which the food cup is formed but in some cases 

 exclusively to the ameba, that is to say, to its degree of hunger. 

 There is therefore no essential differenqe to be observed between 

 Rhumbler's terms 'circumfluenz' and 'circumvallation' except- 

 ing such as is brought about by a varying degree of hunger; and 

 the exact form of the circumfluenz is not any more directly con- 

 ditioned by the shape of the object than is the shape of one's 

 hand conditioned by the pen in writing. In other words, there 

 is no relation whatever between the shape of the object and that 

 of the food cup which encloses it. For these reasons I prefer the 

 one term, food cup, in describing feeding reactions. 



No clear case of ingestion by the 'import' method, which is 

 characteristic of amebas encased in pellicles, has come under my 

 observation (see Rhumbler, '10, p. 194). 



When it was said above that in some cases of feeding no water 

 seems to be taken in with the food object, it was said designedly. 

 Several amebas that had apparently not taken in any water with 

 the food were examined under a compound microscope imme- 

 diately after eating, and in each case a thin film of clear liquid, 

 which may have been water taken in with the food, was seen 

 surrounding the food. This is worth noting, as it throws doubt 

 on whether any food is ever ingested without any water whatever. 



