196 



'IIIK RKItAVIOR OF I.OWKU ORGANISMS. 



friven a very interesting account ofthc rollinj^ up and ingefition of threads 

 of Oscillaria l)y this species (see p. 223).* 



PURSUIT OF FOOD. 



Am<X,ba proirus docs not always succeed in infjesting its food so 

 easily as in the case just descrihcd (p. 194). There is, as noted above, 

 a tendency for the food body to be pushed away by the forward move- 

 ment at the anterior end f)f the Ainn>ba, and this sometimes gives 

 serious difficulty. In such cases Ama>ba may show what would be 

 called in higher organisms remarkable pertinacity in continuing its 



Fig. 73.t 



attempts to ingest the food. This will be illustrated from a concrete 

 case (Fig. 73). 



An Amwha protcus was creeping toward an encysted Euglcna. 

 The latter was perfectly spherical antl very easily moved, so that when 

 the anterior edge of the Amoeba came in contact with it the cyst merely 

 moved forward a little and slipped to one side (the left). The Amonba 



*Leidy 0879, p. 86) fjivcs a very Kimilar account of the ingCHtion of filaments 

 of algno in Dinamdiba. 



tP'u;. 73.- Anidiha following a rolling Euglcna cyst. Nos. 1-9 show successive 

 positions occupied by Ammba and cyst. See text for explanation. 



