20 THE PSYCHIC LIFE 



plain the phenomena of motility among certain Pro- 

 tozoa and Protophytes. 



Nervous System. Hitherto not the minutest trace 

 of a central nervous system has been found in a single 

 Proto-organism. The nervous function among these 

 inferior beings devolves upon the protoplasm, which 

 is irritable, which feels and which moves, and which, 

 in certain species, as we shall see later on, is even ca- 

 pable of performing certain psychic acts, the com- 

 plexity of which seems quite out of proportion to the 

 small quantity of ponderable matter which serves as 

 a substratum to these phenomena. There is, more- 

 over, ng occasion to be surprised that an undifferen- 

 tiated mass of protoplasm should be able to exercise 

 the functions of a veritable nervous system. In fact 

 every nervous element 'is nothing else than the pro- 

 duct of protoplasmic differentiation; the protoplasm 

 embodies in itself all the functions that, in conse- 

 quence of an ulterior division of labor among the 

 pluricellular organisms, have been assigned to distinct 

 elements. 



It has rightly been held, therefore, that if no nerv- 

 ous system, anatomically differentiated, existed in 

 proto-organisms, it must be admitted that their pro- 

 toplasm contains a diffused nervous system. Among all 

 the observations that uphold this idea, we must cite 

 one to which M. Gruber, a professor at Freiburg, in 

 Breisgau, has recently called attention. This obser- 

 vation was made on a large, ciliated Infusory, the 

 Stentor, of which mention will be made so often here- 

 after that it will be advantageous to give a full de- 

 scription of it beforehand. 



The Stentor has an elongated body, broadened in 

 front like a funnel, and able to fasten itself by its pos- 



