II 



PHYLUM PROTOZOA 



57 



which is traceable through the general protoplasm as far as the 



nucleus. Living organisms are de- 



voured in much the same way as in 



Amoeba: each is ingested along with 



a droplet of water, and is thus seen, 



during digestion, to lie in a de- 



finite cavity of the protoplasm, 



called a food-vacuole. If the or- 



ganism be small, processes of the 



protoplasm are developed, and sur- 



round and engulf it. If it be larger, 



several pseudopods are applied to 



it, their axial fibres becoming ab- 



11 j ,1 r i 



sorbed, and their substance envelops 



if Anplncinrr if in a var-nnlp Tho 

 It, enclosing It in a VaCUO 



animal can fix itself by means of 



its pseudopods, the ends of which become viscid, and it is able 



to crawl slowly by their means. Sometimes it floats freely in the 



FIG. 3<k Actinophrys sol. a. axial 



filaments of pseudopods ; . nucleus ; 



P- pseudopod. (From Lang's Com- 

 ive. Anatomy, after Grenadier.) 



rrucl 



nu 



FIG. 40. Actinosphserium eichhornii. A, the entire organism ; B, a small portion 

 highly magnified ; chr. chromatophore ; cort. cortex ; c. vac. contractile vacuole ; med. medulla ; 

 n u. nuclei. (From Blitschli's Protozoa, after Hertwig and LesseT.) 



water, and it possesses the power of rising or sinking by some 

 unknown means. 



Actinosphcerium (Fig. 40, A), another fresh-water form, is more 



