446 PROGRESS OF SCIENCE IN THE CENTURY. 



specialised centres both sensory and motor. And to 

 this experimental investigation there has come aid 

 from histological studies, especially since the refine- 

 ment of methods due to Golgi and Ramon y Cajal. 



Although a splendid beginning has been made, 

 It is only a beginning, and even among experts there 

 is much diversity of opinion on important questions. 

 Thus we find Flechsig mapping out three levels 

 of centres in the cortex, sense-centres (also motor), 

 association-centres (with indirect motor connections), 

 and between these in order of development inter- 

 mediate centres; while, on the other hand, we find 

 Loeb * maintaining that while there exists to a cer- 

 tain extent an anatomical localisation in the cortex, 

 the assumption of a physical localisation is contra- 

 dicted by the facts. ... M In processes of associa- 

 tion the cerebral hemispheres act as a whole, and not 

 as a mosaic of a number of independent parts, . * 

 It is just as anthropomorphic to invent special centre* 

 of association as it is to invent special centres of co- 

 ordination." f 



SUMMARY. It must be admitted by all that 

 " there exist manifold correspondences of the most in- 

 timate and exact kind between states and changes of 

 consciousness on the one hand, and states and changes 

 of brain on the other. As respects complexity, in- 

 tensity, and time-order the concomitance is appar- 

 ently complete. Mind and brain advance and decline 

 pari passu; the stimulants and narcotics that en- 

 liven or depress the action of (he one tell in like 

 manner upon the other. Local lesions that suspend 

 or destroy, more or less completely, the functions of 



Loeb, Comparative rhytiology of the Brain (1900), 

 p. 262. 

 f Loeb, p. 27* 



