io5 IGNORABIMUS ET RESTRINGAMUR. 



by the division of labour of the cells out of those 

 neutral cell-groups in their lower-typed ancestors. 



In the great Soul-question Du Bois-Eeymond, like 

 Virchow, still keeps his position on the standpoint of 

 neural-psychology, according to which no personal 

 soul-life is conceivable without a nervous system. We 

 look upon this standpoint as left far behind, and set 

 up in opposition to it Cellular-psychology, the doctrine 

 that every animal cell has a soul ; that is to say, that 

 its protoplasm is endowed with sensation and motion. 

 In the one-celled infusoria, which are so highly sensi- 

 tive and have such an energetic will, this conception 

 will be clear without any farther explanation. But 

 we cannot refuse to allow that plant-cells as well as 

 animal-cells have psychic functions, since we know 

 that the phenomena of irritability, and of " automatic 

 motion," are the universal attributes of all protoplasm. 

 No doubt the specific mechanism, the cause of motion, 

 in the irritable Mimosa and other " sensitive " plants, 

 is quite different from the muscular motions of ani- 

 mals ; but these, like those, are only specifically 

 different forms of development of the " cell-soul," and 

 both proceed from the " mechanical energy of the 

 protoplasm." The sensibility of the irritable proto- 

 plasm is the same in the vegetable-cell of the Mimosa 

 as in the animal-cell of the Hydra. How far Du Bois- 

 Eeymond is from discerning this, and how deeply he 



