266 CREATIVE EVOLUTION 



a considerable number of motor mechanisms are set 

 up in the medulla and in the spinal cord, awaiting only 

 a signal to release the corresponding act : the will is 

 employed, in some cases, in setting up the mechanism 

 itself, and in the others in choosing the mechanisms 

 to be released, the manner of combining them and 

 the moment of releasing them. The will of an animal 

 is the more effective and the more intense, the greater 

 the number of the mechanisms it can choose from, the 

 more complicated the switchboard on which all the 

 motor paths cross, or, in other words, the more developed 

 its brain. Thus, the progress of the nervous system 

 assures to the act increasing precision, increasing variety, 

 increasing efficiency and independence. The organism 

 behaves more and more like a machine for action, which 

 reconstructs itself entirely for every new act, as if it 

 were made of india-rubber and could, at any moment, 

 change the shape of all its parts. But, prior to the 

 nervous system, prior even to the organism properly 

 so called, already in the undifferentiated mass of the 

 amoeba, this essential property of animal life is found. 

 The amoeba deforms itself in varying directions ; its 

 entire mass does what the differentiation of parts will 

 localize in a sensori-motor system in the developed 

 animal. Doing it only in a rudimentary manner, it is 

 dispensed from the complexity of the higher organisms ; 

 there is no need here of the auxiliary elements that pass 

 on to motor elements the energy to expend ; the animal 

 moves as a whole, and, as a whole also, procures energy 

 by means of the organic substances it assimilates. Thus, 

 whether low or high in the animal scale, we always find 

 that animal life consists (i) in procuring a provision of 

 energy ; (2) in expending it, by means of a matter as 

 supple as possible, in directions variable and unforeseen. 



