1932] Poliak: Afferent Fiber Systems, Primate Cerebral Cortex 207 



according to which a "mathematical projection" of the retina upon 

 the cerebral cortex is achieved, the same principle applying- also to a 

 part of the further, subcortical association connections of the visual 

 projection cortex with the surrounding non-projection areas of the 

 oecipito-parietal lobes. The second principle (or principles), entirely 

 insecure, as yet, possibly coexisting with the first, postulates the exist- 

 ence of short intracortical and subcortical neurons, mechanisms which 

 are responsible for the unity of subjective psycho-visual experiences. 

 (Nothing definite about this minute integrative sj'^stem can be said at 

 the present time since, beyond a few hints given by Hamon y Cajal, no 

 investigations concerning it have been made ; the necessity of postulat- 

 ing side by side with the "localized" structures others lacking the 

 defijiiteness and specificity or possessing these in a small degree only, 

 particularly within the cerebral cortex, is stressed by Lashley and by 

 Gurwatsch.) 



