102 CELL INTELLIGENCE THE CAUSE OF EVOLUTION 



table or animal decomposition. Saprophytic beings are 

 found in putrid waters or in infusions. 



"There is now a last mode of nutrition, of which we 

 shall treat in minute detail ; viz., animal nutrition, where 

 the micro-organism seizes solid alimentary particles and 

 nourishes itself after the fashion of an animal, whether 

 it be by means of a permanent mouth or by means of 

 an adventitious one improvised at the moment of need. 



"Animal nutrition requires very remarkable psycholog- 

 ical faculties in the organisms practising it. These mani- 

 festations of psychic life, the progressive complexity of 

 which we intend to trace in starting from the simplest 

 protozoic forms and arriving at the higher, prove that 

 these animalcula are endowed with memory and volition. 



"The micro-organisms do not nourish themselves in- 

 discriminately, nor do they feed blindly upon every sub- 

 stance that chances in their way. Also when they ingest 

 food through some point or other of their bodies, they un- 

 derstand perfectly how to make a choice of the particles 

 they wish to absorb. This choice is sometimes quite well 

 defined, for there are species which feed exclusively upon 

 particular foods. Thus there are herbivorous Infusoria 

 and carnivorous Infusoria. Among the herbivorous ones 

 may be classed the chilodons, which feed upon small algae 

 diatomaceae and Oscillaria. The paramecia live princi- 

 pally upon bacteria, the leucophrys is a specimen of the 

 carnivorous class. It devours even the smaller animals of 

 its own kind." 



"The Bodo caudatus is a voracious flagellate possessed 

 of extraordinary audacity. It combines in troups to at- 

 tack animalcules 100 times as large as itself as the colpods 

 for instance, which are veritable giants when placed along 

 side of the Bodo. Like a horse attacked by a pack of 

 wolves, the colpod is soon rendered powerless ; twenty, 



