PREFACE xv 



note of the infusorium, and ends with the grand 

 symphony of the mammal, in which millions of cell- 

 voices take part. And when the volume of sound 

 of the organic orchestra reaches its highest note, 

 again rises the enchanting refrain of the germ, 

 that is, the simple cadences of the ovule, starting 

 from which the melody develops with a crescendo, 

 ever more complicated, until arriving again at the 

 fullness of the modulations and motives of the 

 organisation of the adult. 



In no organic apparatus do we find this rhythmic 

 character in greater relief than in the cerebral 

 instrument. Our mind is nourished on waves 

 gathered from all parts of the cosmos, and its 

 principal mission consists in classifying, combining, 

 and reflecting them, with reference to their 

 origin. Perceptions, ideas, the spoken word, even 

 muscular contraction, what are they, in their 

 ultimate analysis, but palpitations of heat, of light, 

 of chemical energy, of electricity, etc., transformed, 

 refined, and converted into other palpitations more 

 subtle and spiritual? Like a lens of singular 

 virtue and power, our nervous system gathers all the 

 noises and minute tremblings in the world, in order 

 to concentrate them, now in the splendid form of 

 an idea, now in the flame of will and of passion. 



If viewing the animal series as a chromatic scale, 

 as a symphony executed by natural forces that, 



