AND CELLULAR PSYCHOLOGY. 59 



foundation of empirical psychology," I believed I was 

 drawing an inference quite to Virchow's mind, from 

 liis own views of mechanical and cellular-physiology ; 

 and for that reason I took the same occasion specially 

 to celebrate his very great services to the cell theory. 

 How astonished then was I when in his reply this very 

 theory was violently attacked and satirised as " mere 

 trifling with words." It never could have occurred to 

 me that Virchow had long since become unfaithful to 

 his most important biological principles, and had de- 

 serted his own mechanical " theory of cells ; " it never 

 had occurred to me that Virchow could be in great 

 measure wanting in that zoological knowledge which 

 is requisite for a practical comprehension of the cell- 

 soul theory. He has never thoroughly studied either 

 the one-celled Protozoa, the Infusoria and Lobosa, 

 nor the Coelenterata, the highly instructive Sponges, 

 Hydroids, Medusae, or Siphonophora ; and thus he is 

 wanting in those genetic principles of comparative 

 zoology on which our theory rests. It is in no other 

 way conceivable that Virchow should contemn the 

 most important consequences of the cell theory as 

 " mere trifling with words." 



Next to the one-celled infusoria no phenomenon 

 throws such direct light on our cellular psychology as 

 the fact that the human ovum, like the ova of all 

 other animals, is a single, simple cell. In accordance 



