AND CELLULAR PSYCHOLOGY. 57 



must possess nerves and muscles, organs of sense and 

 of soul, as well as the higher animals. 



It is well known that the enormous advance which 

 our science has lately made in the natural history of 

 these lowest organisms culminates in the statement 

 clearly made by Siebold thirty years since, but only 

 recently " ascertained as proved " that these minute 

 creatures are one-celled^ and that in the case of these 

 infusoria one single cell is capable of all the various 

 vital functions- including soul - functions which in 

 the zoophytes (plant-animals), as the hydra and the 

 sponges, are distributed among the cells of the two 

 germ-layers, and in all the higher animals among the 

 different tissues, organs, and apparatus of a highly 

 developed and constructed organism. The psychic 

 functions of sensation and voluntary motion, which 

 are here distributed to such very various organs and 

 tissues, are in the infusoria fulfilled by the neutral 

 plasson material of the cell, by the protoplasma, and 

 possibly also by the nucleus (compare my treatise, 

 " The Morphology of the Infusoria." Jena, Zeitschrif- 

 ten, 1873, vol. vii. p. 5 1 6). And just as we must attri- 

 bute to these primary animal forms an independent 

 " soul," just as we must plainly be convinced that the 

 single independent cell has a " psyche," we must as 

 decidedly attribute a soul to every other cell ; for the 

 most important active constituent of the cell, the proto- 



