REFLEX AND CONDITIONED ACTION 63 



overt expression may be as numerous and the total 

 time of learning may be greatly prolonged. We say 

 in this case, the problem is solved by ''insight,'* but 

 this does not tell us anything about what the insight 

 is or its mechanism. Apparently, the more impres- 

 sionable cortex receives and holds records of indi- 

 vidual experience more readily than does the thala- 

 mus; these records can be woven into new patterns; 

 inventiveness takes the place of blundering or random 

 attack upon an unfamiliar situation; progressively 

 more of the behavior is transferred from the explicit 

 to the implicit form. 



This, briefly, seems to be the history of the elabo- 

 ration of the apparatus of correlation in the vertebrate 

 series as viewed in its physiological aspects. Our 

 knowledge of the anatomical mechanisms involved is 

 still inadequate, but enough is known of this subject 

 to permit a tolerably good parallel outline of the 

 structural evolution of the nervous system and the 

 minute details of its internal organization. Limita- 

 tions of space forbid the presentation of this anatomi- 

 cal detail in this work except in meager outline. 



In the preceding discussion the attempt has been made to 

 avoid dogmatism about the actual mechanisms employed in con- 

 ditioned reactions while outlining a ^theoretic analysis which 

 seems best to fit all of the known facts. There is ample room for 

 other explanations. Lashley (1924^) has, in fact, performed a 

 useful service in demanding a critical re-examination of the cur- 

 rent views here summarized, and his comments merit brief con- 

 sideration. 



