158 THE RIDDLE OF THE UNIVERSE. 



settled, it does not alter the fact that these unicellular 

 protozoa give proof of the possession of a highly- 

 developed " cell-soul," which is of great interest for 

 a correct decision as to the psyche of our earliest 

 unicellular ancestors. 



II. The communal or cenobitic soul (coenopsyche) : 

 second stage of phyletic psychogenesis. — Individual 

 development begins, in man and in all other multi- 

 cellular animals, with the repeated segmentation of 

 one simple cell. This stem-cell, the impregnated 

 ovum, divides first into two daughter- cells, by a 

 process of ordinary indirect segmentation ; as the 

 process is repeated there arise (by equal division of 

 the egg) successively four, eight, sixteen, thirty-two, 

 sixty-four, such new cells, or " blastomeres." Usually 

 (that is, in the case of the majority of animals) an 

 irregular enlargement sooner or later takes the place 

 of this original regular division of cells. But the 

 result is the same in all cases — the formation of a 

 (generally spherical) cluster of heterogeneous (origi- 

 nally homogeneous) cells. This stage is called the 

 morula (" mulberry," which it somewhat resembles in 

 shape). Then, as a rule, a fluid gathers in the interior 

 of this aggregate of cells ; it changes into a spherical 

 vesicle ; all the cells go to its surface, and arrange 

 themselves in one simple layer — the blastoderm. The 

 hollow sphere which is thus formed is the important 

 stage of the ''germinal vesicle," the blastula, or 

 blastosphere. 



The psychological phenomena which we directly 

 observe in the formation of the blastula are partly 

 sensations, partly movements, of this community of 

 cells. The movements may be divided into two 

 groups : (1) the inner movements, which are always 



