1923] 



Swezij: Pseudopodial Method of Feeding 



397 



length of the flagellates. The larger pieces are engiilfed as freelj' 

 as smaller ones. Occasionally Leidyopsis may be found to have 

 mastered a piece of wood so long that the body of the flagellate 

 becomes stretched out several times its own u.sual width, forming a 

 grotesque caricature of its customary appearance (fig. 10). It is 

 also not uncommon to see pieces so long that the ends project beyond 

 the two sides of the bodv. 



Figs. 10-11. Leidyopsis sp., drawn from living specimens. Note huge size 

 of food boilies ingested. X 300. 



The smaller flagellates, such as Trichomitus, may become the prey 

 of both Trichonympha and Leidyopsis. An individual of the latter 

 genus was noted with an engulfed Trichomitus that was rapidly 

 rotating in a vacuole in the posterior part of the body. This indi- 

 vidual was watched for about one hour when its movements had 

 become slowed down. The vacuole did not have the appearance of 

 the ordinary food vacuole but seemed to have been formed by the 

 activities of the Trichomitus. 



Particles may also be ejected from the body in the posterior 

 region. The ectoplasm here lacks the .structural differentiation char- 

 acteristic of the anterior portion of the body as well a.s the ciliary 

 coating of flagella (fig. 1). No evidences of an attempt to engulf 

 or eject food particles through the differentiated ectoplasm of the 

 anterior region have been seen. 



