GENERAL PHYSIOLOGY 



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side of the object and meet around it, thus enclosing a rotifer, an 

 Arcella, a diatom or other food body. Ingestion by "circum- 

 fluence" appears to be due to a stimukis emanating from a living 

 food body, the effect of which through the motor response (Jennings, 

 1904) is to cause pseudopodia to flow toward the prey and to entrap 

 it while still at some distance from the body of the captor as in the 

 testate rhizopods and Foraminifera. "Invagination" occurs in 

 forms having a somewhat resisting periplast-like ectoplasm such as 



Fig. 50. — Two types of ciliated carnivores. A, Spathidhim spathula aVjout to 

 ingest a Colpidium colpoda; B, Lionohis fasciola swallowing a Colpidium colpoda. 

 (Original.) 



Amoeba terricola according to Grosse-Allermann (1909). When a 

 living organism comes in contact with the surface at any point, the 

 local ectoplasm with prey attached sinks into the endoplasm as 

 though "sucked" in, the ectoplasmic walls being transformed into 

 endoplasm, while the ectoplasm about the area of ingestion comes 

 together sphincter-like, and fuses again to a smooth surface. So, 

 too, in A. protevs where, according to Mast (1916 and 1923) and 

 Beers (1924) the sphincter-like ingesting area is powerful enough to 

 cut in two organisms like Paramecium and Frontonia. Ingestion 



