1 84 From Matter to Man. 



contractile vacuole (some algae also possess the same), 

 which appears and disappears every few seconds. 

 Probably it is an incipient heart, lung, stomach, and 

 excretory apparatus all in one ; for, in rudimentary 

 organisms, one organ performs many different func- 

 tions afterwards specialised. Thus, as Darwin ob- 

 served, the alimentary canal respires, digests, and 

 excretes in the larva of the dragon-fly, and in the fish 

 cobites ; while in the hydra, if the animal be turned 

 inside out, what was the exterior surface digests and 

 the stomach respires. 



The amoeba feeds, like other pseudopodial creatures, 

 by engulfing infusoria and other minute life in its 

 protoplasm which its shoots over its victims in streams. 



Summing up its life-processes, an amoeba is capable 

 of finding, seizing, devouring, digesting, and assimi- 

 lating food ; it has a special provision for collecting 

 fluid and pumping it out of its body ; it respires by 

 its whole surface ; it moves about apparently where it 

 wills ; it exhibits a sensibility to tactile impressions, 

 and reacts in all probability to smell, if not to sound 

 and light. In short, it is capable of performing rudi- 

 mentarily almost every function which animals vastly 

 higher in the scale of organisation exhibit.* The 

 amoeba is, however, lower in its reproductive processes 

 than the protomonas, for it divides by fission like 

 the protomoeba, each half retaining half also of the 

 nucleus. 



The eggs or ovules of many low animals are virtu- 



* "Article Histology," Ency. Brit. 



