38 SUPER-ORGANIC EVOLUTION 



In the gastrula the cells store these vibrations, 

 whose weak potentiality is diffused through the 

 whole animal and is fortified by the radiation and 

 the contiguity of some cells with others. The 

 constancy and persistency of the rhythm lead to 

 their narrow limits being overstepped ; the currents 

 forming the radiations of the movement which is 

 necessarily spread from every cell cause these to 

 lengthen their substance for the better transmission 

 and distribution of the rhythm or incitation to a 

 distance, and thus the nervous filaments (the 

 prolongations of the real cellular substance) are 

 formed by rhythmic impulses of energy. Thus we 

 see that the origin of the nerve-filament is due to 

 the constancy and persistence of the inciting cause. 

 The form adapting itself to the movement is the 

 result of a system of rhythms, and the neurona, 

 by its tardy appearance in the organic evolution, 

 obeys, as we have seen, more complex rhythms. 

 Its form obeys the resultant of certain determinate 

 movements, and thus, as we saw how sand in a 

 glass bowl forms regular figures through the 

 rhythm of the vibration communicated to the 

 crystal, so the neurona also owes its form to the 

 result of the rhythms which it alone can perceive 

 and interpret. 



Nobody can doubt that the lowest animals, like 

 sponges, polypi, etc., are an effect of the natural 



