50 E. RAY LANKESTER 



excellent " automata " had to give place by natural sélection in ihe 

 struggle for existence, to the gradually increasing brains wilh their greater 

 power of mental adaptation to the changing and varied conditions of life : 

 imtil in man an organism bas been developed which though differing but 

 little in bodily structure from the monkey, has an amount of cérébral tissue 

 and a capacity for éducation which indicates an enormous period of graduai 

 development during which not the gênerai structure but Ihe organ of 

 " educability " the cerebrum was almost solely the objective of sélec- 

 tion. 



Two lines of spéculation and enquiry aro strongly affected by the hypo- 

 thesis thus stretched. 



Firstly, as to the gênerai laws of progressive development of bodily 

 structure by [the opération of natural sélection — is it not probable that 

 in varions groups of animais, just as in the case of man among the Primates, 

 the opération of natural sélection on bodily structure (limbs, teeth, hair, 

 horns, etc.) must havc been cbecked or even altogether suspended, by the 

 transference of sélection to the ail-important organ of educability the cere- 

 brum or corresponding nerve-centres? Adaptation by means of the mental 

 powers must take the place of adaptation of bodily structures. The educable 

 animal leaves the ground and learns to climb trees in order to gain its food 

 whilst in another race the slowcr process of altération of bodily form is 

 cvolving a long neck to reach the green twigs, or a pondérons strength 

 of limb which can pull trees to the ground. Many similar cases will suggest 

 themselves to the reader in which even in lower animais, the capacity 

 of learning by expérience, must (as it were) defeat and turn from its route 

 the otherwise triumphant transformation of bodily structure. 



Secondly, the question of the transmission of acquired characters, is 

 largely touched by thèse spéculations. The character which we describe 

 as " educability " can be transmitted, it is a congénital character. But the 

 results of éducation can not be transmitted. In each génération they hâve to 

 be acquired a-fresh, and with increased " educability " they are more readily 

 acquired and a larger variety of tliem. On the other hand the nerve- 

 mechanisms of instincts are transmitted, and owe their inferiority as 

 compared with the results of éducation to the very fact that they are not 

 acquired by the individual in relation to his particular needs, but bave 

 arisen by sélection of congénital vai'iation in a long séries of preceding 

 générations. 



To a large extent the two séries of brain-mechanisms the " instinctive '' 

 and the " individually acquired '", are in opposition to one another. 

 Congénital brain-mechanisms may prevent the éducation of the brain and 

 the development of new mechanisms specially fitted to the spécial condi- 

 tions of life. To the educable animal — the less thcre is of specialized 



