THE PHYLOGENY OF THE SOUL. 157 



from a physiologico-chemical point of view, that the 

 very earliest protists were plasmodomous, with plant- 

 like nutrition — hence protophyta, or primitive plants ; 

 from these came as a secondary stage, by metasitism, 

 the first plasmophagi, with animal nutrition — the 

 protozoa, or primitive animals. 1 This metasitism, or 

 circulation of nutritive matter, implies an important 

 psychological advance ; with it began the development 

 of those characteristic properties of the animal soul 

 which are wanting in the plant. 



We find the highest development of the animal 

 cell-soul in the class of ciliata, or ciliated infusoria. 

 When we compare their activity with the corresponding 

 psychic life of the higher, multicellular animals, we 

 find scarcely any psychological difference ; the sen- 

 sitive and motor organella of these protozoa seem to 

 accomplish the same as the sense-organs, nerves, and 

 muscles of the metazoa. Indeed, we have found in 

 the great cell nucleus (meganucleus) of the infusoria a 

 central organ of psychic activity, which plays much 

 the same part in their unicellular organism as the 

 brain does in the psychic life of higher animals. 

 However, it is very difficult to determine how far this 

 comparison is justified ; the views of experts diverge 

 considerably over the matter. Some take all spon- 

 taneous bodily movement in them to be automatic, or 

 impulsive, and all stimulated movement to be reflex ; 

 others are convinced that such movements are partly 

 voluntary and intentional. The latter would attribute 

 to the infusoria a certain degree of consciousness, and 

 even self-consciousness; but this is rejected by the 

 others. However that very difficult question may be 



1 Cf. E. Haeckel, Systematic Phylogeny, vol. i. 



