The Relatmi of Orga?iic to Mental Evolution. 265 



and alterations of its machinery during the lifetime of the 

 individual. How otherwise could an animal have any 

 power of individual acquisition ? But while heredity pro- 

 vides a power of individual acquisition, it does not provide 

 in advance for particular innovations or modifications. A 

 store of/^mmtepower, a"d defin ite susce ptibilities to 

 pleasure and^oain^IariLJiflierited ; individual experience 

 utilizes tWsinnate power to mould its instinctive and 

 other activities into new habits under the guidance of 

 pleasure and pain. And this absence of provision in 

 advance for particular modifications is probably what 

 Eomanes meant. Apart from this, he ^seems jo have quite 

 clearly indicated a valid criterion».o X the effective presence 

 of consciousness — namely, the observable, profiting by 

 experience. It is just because a chick, havingtasted a 

 nasty grub, refuses to touch it or its like for the future, 

 that we may feel confident he exercises real choice in the 

 matter. Invariable response under similar conditions, 

 as in the case of the spermatozoids in the presence of 

 malic acid, is no evidence of choice ; but an alteration or 

 modification of response in the light of individual 

 experience does afford the criterion we seek. And this 

 criterion involves the exercise of control. Au tomatism , no 

 matt er how c omp lex or how nicely adap tive, ma y be un- 

 conscious ; but controlled action indicates conscious choice. 

 "Whatever the physiologicaTconditions of the process 

 may be, it seems clear that consciousness, as choosing and 

 controlling, stands in a sense "outs i3e*^taTl ipon which it 

 exercises con trol th ronflh its po.Tjpr of ohm™. And, thus, 

 on passing from the merely organic to the conscious- 

 organic phase of evo lution, we nave to consider the develop- 

 ment of an impexium in imperio. In close touch and 

 intimate relation with the merely organic and automatic 

 system is a controlling system, the functional activity of 



