PHYLOGENY AND ONTOGENY OF NEURONA 65 



or basiliary in the cylindric axis. The corpuscule 

 b shows some protoplasmic expansions at its base. 

 All the structural elements go on complicating 

 together with the evolution of the psychic cell, as 

 we see in corpuscule c. 



And for the comprehension of the great psychic 

 unity in the whole organisation figs. 14 and 15 

 give a sketch of the olfactory and visual senses 

 of man. 



In these diagrams we see represented all the 

 types of neuronas which we have seen in the 

 phylogenic and ontogenic series, starting from 

 the bipolar type. The structure of these senses 

 consists principally in the immense multiplication 

 of the neuronas ; the variation in the form is of 

 minor importance. 



From this structure of the senses in man we 

 clearly see how they have been formed by the 

 successive integration and multiplications of the 

 neurona as, for example, to start with the eye, 

 the coloured spots in the worm have become the 

 perfectly formed optic organ of the human being. 

 The same causes, light and the external world, 

 which elaborated the former, are those which gave 

 rise to the structure of the cerebral centres of smell 

 and sight, etc., in the human brain, and hence all 

 cerebral is a reflection of mechanical structure. 



