H4 THE PSYCHIC LIFE 



theory of the sarcode. There are really no simple organisms, 

 and such as appear so are merely imperfectly known. 



However, it will not do perhaps to take literally the terms em- 

 ployed by M. Richet. When he speaks of homogeneous cellules it 

 is possible that he wishes to speak merely of cellules in which, aside 

 from the nucleus, no other differentiated organ is to be found. 



Now, it is quite important to note that, even of organisms 

 made up simply of protoplasm and nucleus, the psychology is ex- 

 tremely complicated, and is not contained exclusively in the laws 

 of irritability. 



The Vampyrella Spirogyra, classed by Zopf among the animal- 

 fungi, and the place of which is still so little known, is a being the 

 body of which is composed of protoplasm and nucleus simply. 

 So far no other differentiated organ has been found in this creature, 

 except from one to four contractile vesicles. Employing the ter- 

 minology of M. Richet, perhaps we ought to call this being a sim- 

 ple cellule; yet this simple cellule has quite a complicated psy- 

 chology: it exercises choice in the selection of its food, attacking 

 Spirogyra only. 



The same is the case with the Monas amyli, which, having 

 neither eye nor mouth, represents to M. Richet a simple cellule; 

 still, the Monas amyli exercises choice in selecting its food, as it 

 feeds exclusively on grains of starch. 



The structural elements of the tissues do not differ from the 

 micro-organisms whose psychological history I have endeavored to 

 unfold, so much as might be imagined: they show the same powers 

 of selection, and on this point I shall only instance the epithelial cel- 

 lules of the intestines or the phagocyte cellules, the attributes of 

 which I have described in my essay, and which are able to dis- 

 criminate, for instance, between bits of fat and particles of coal, 

 absorbing the former and leaving the latter. 



I repeat it, therefore, no living cellule, strictly so defined, is a 

 simple cellule, and I do not think that M. Richet has advanced a fit- 

 ting illustration in mentioning the muscular cell, for the latter is 

 one of the most highly differentiated that there are. 



I cannot imagine, accordingly, to what elements, to what be- 

 ings clearly defined, we could apply the simple-cellular psychology 

 reduced to mere irritability, that M. Richet asks me to distinguish 

 from the complex-cellular psychology, which would be exclusively 

 reserved for the animal and vegetable micro-organisms that I have 

 described. 



