30 MIND IN EVOLUTION CHAP. 



adverse circumstances, we find it, on the other, departing 

 from its type to suit special circumstances. The growth 

 and maintenance of the organism are due, not merely to a 

 complex balance of internal forces, but also to compli- 

 cated reactions between these forces in their successive 

 phases and the forces of the environment. 



4. What appears to be the distinguishing mark of an 

 organism is that, through all these complications, it main- 

 tains its hold on the balance of forces necessary to its 

 existence. It is not merely that its functions run smoothly 

 in the particular groove marked out for them by its struc- 

 ture, but that, within tolerably wide limits, it can survive 

 accidents, which cause a considerable departure from its 

 normal course, and either struggle back to the typical life 

 of the species again, or effect some compromise with cir- 

 cumstances by which life is maintained in some more or 

 less modified form. Adaptability of this kind does not 

 seem to be found in the inorganic world. A stone main- 

 tains its existence for centuries, it may be, but maintains it 

 unchanged. If the stone could be said to have a life, it 

 would be one of dull mechanical persistence in the estab- 

 lished fact. If it is scratched, dinted, or broken, it remains 

 scratched, dinted, or broken, and there is no more to be 

 said. There is nothing comparable to the recuperation 

 of the living being. 



It may very well be true that, if we take the common char- 

 acteristics of organised beings one by one, and look about 

 us for comparisons, we can find something to match each 

 one severally in the inanimate world. Thus the tendency 

 to regain the equilibrium point is common to mechanical 

 arrangements, like the pendulum, and to all bodies so far 

 as they are elastic. The analogy is real so far as it goes. 

 In one particular way the elastic body can be made to 

 deviate from, and then will tend to return to, an equilibrium 

 point. But the tendency is limited to a single kind of 

 reaction ; it is called into being only by the application of 

 an external force, to which the reaction is strictly pro- 

 portioned, and the existence of the object as an elastic 

 body does not consist in, nor depend upon, a state of con- 

 stant activity in oscillating about the point of equilibrium. 



