EHIZOPODA. 7 



and are far less mutable than the same parts in 

 Aoiioeba. The body of Actinophrys, when mag- 

 nified {fig, 3, 6), is seen to be composed of a 

 simple homogeneous sarcode substance, filled with 

 granules and ' vacuoles,' in the midst of which a 

 true ' contractile vesicle ' may, in most cases, be 

 readily perceived. The mode in which this Ehi- 

 zopod takes food is peculiar, and has been care- 

 fully observed by Kolliker. Should a small Crus- 

 tacean, Eotifer, or any other of the minute active 

 animals upon which the Actinojph^s is accus- 

 tomed to feed, come in contact with one of the 

 radiating filaments, it soon adheres to the latter, 

 which slowly shortens until it approaches the 

 surface of the body, the filaments in its neigh- 

 bourhood bending around it, so that the prey be- 

 comes surrounded on all sides. The pseudopodia 

 then gradually diminish in length, until that by 

 which the prey was first seized altogether disap- 

 pears. At this spot a depression begins to be 

 formed, in which the captured animal is lodged 

 (fig. 2, a, 6). This depression becomes deeper 

 and deeper, the pseudopodia around it again elon- 

 gate, and finally its outer edges coalesce, so that 

 the prey becomes enclosed in a cavity. Here it 

 remains until digested, after which the cavity 

 contracts, and finally disappears. But should any 

 indigestible particles remain, these are expelled 

 by renewed contractions of the sarcode body, usu- 

 ally in the same direction by which they were 

 originally taken in. 



In both of the Ehizopods already noticed the 

 body is completely naked. In some -4mce6ce, in- 

 deed, its outer portion would seem to possess a 



6 4 



