88 SYMBIOGENESIS 



the recognition of which he was otherwise so well equipped by 

 his whole training. Let us see. 



As regards the laws of organic modification failing the 

 bio-economic explanation Spencer is somewhat at sea and can 

 but "dimly discern a harmony" with his famous first 

 principles. 



" Why an organ exerted somewhat beyond its wont, should 

 presently grow, thus meet increase of demand by increase of 

 supply, is not obvious." That excess of repair should succeed 

 excess of waste, is to be expected. " But how happens the 

 mean state of the organ to be changed? If daily extra waste 

 naturally brings about daily extra repair only to an equivalent 

 extent, the mean state of the organ should remain constant." 



Clearly we must look for an explanation somewhere out- 

 side Spencer's First Principles. Indeed, he himself makes 

 the attempt in what I consider to be the right direction, 

 although being too much committed to his mechanical First 

 Principles and to his definition of life, he shrinks from 

 drawing the wider bio-economic conclusions, which neverthe- 

 less easily arise from the consideration he sets before us. 



Says he : 



Such answer to this question as we may hope to find, must be 

 looked for in the effects wrought on the organism as a whole, by increased 

 function in one of its parts. For since the discharge of its function by 

 any part, is possible only on condition that those various other functions 

 on which its own is immediately dependent, are also discharged ; it 

 follows that excess in its function presupposes some excess in their 

 functions. Additional work given to a muscle implies additional work 

 given to the branch arteries which bring it blood, and additional work 

 smaller in proportion to the arteries from which these branch arteries 

 come. Similarly, the smaller and larger veins which take away the 

 blood, as well as the absorbents which carry off effete products, must 

 have more to do. And yet further, on the nervous centres which excite 

 the muscle, a certain extra duty must fall. But excess of waste will 

 entail excess of repair in these parts as well as in the muscle. The 

 several appliances by which the nutrition and excitation of an organ 

 are carried on, must also be influenced by this rhythm of action and 

 reaction and, therefore, after losing more than usual by the destructive 

 process, they must gain more than usual by the constructive process. 



