98 PROTOZOOLOGY 



the part of the amoeba (a); (2) by "circumfluence,'' in which the 

 cytoplasm flows around the food organism as soon as it comes in 

 contact with it on all sides and engulfs it (6) ; (3) by "circumvalla- 

 tion," in which the amoeba without contact with the food, forms 

 pseudopodia which surround the food on all sides and ingest it (c) ; 





Fig. 33. Various ways by which amoebae capture food organisms, 

 a, A moeba verrucosa feeding on Oscillatoria by 'import' (Rhumbler) ; b, A . 

 proteus feeding on bacterial glea by 'circumfluence'; c, on Paramecium 

 by 'circumvallation' (Kepner and Whitlock) ; d-h, A. verrucosa ingesting 

 a food particle by 'invagination' (Gross-Allermann). 



(4) by "invagination," in which the amoeba touches and adheres to 

 the food, and the ectoplasm in contact with it is invaginated into the 

 endoplasm as a tube, the cytoplasmic membrane later disappears 

 (d-h). In a species of Hartmannella, Ray (1951) reports an aggluti- 

 nation of large numbers of motile bacteria over the body surface, 

 which later form a large mass and are taken into a food cup. 



In certain testaceans, such as Gromia, several rhizopodia cooper- 

 ate in engulfing the prey and, in Lieberkuhnia (Fig. 34), Verworn 

 noted ciliates are captured by and digested in rhizopodia. Similar 



