488 Dr. A. W. Campbell. [Nov. 17, 



" Histological Studies on Cerebral Locali Ration." By ALFRED W. 

 CAMPBELL, M.D. Communicated by Professor C. S. SHERRING- 

 TON, F.K.S. Keceived November 17, Read December 3, 

 1903. 



(Abstract.) 



Introduction. 



The essential aim of this work is to further the establishment of a 

 correlation between physiological function and histological structure. 



The present communication deals with the central gyri, the occipital, 

 temporal and limbic lobes ; but an account of the remainder of the 

 cortex, viz., that of the frontal and parietal lobes and the insula, will 

 be presented to the Society at a later date. 



I. Material and Methods. 



The normally existent topographic variations in arrangement of 

 cortical nerve cells and medullated nerve fibres have been adopted as a 

 standard criterion in forming judgment on points bearing on localisation, 

 and a thorough examination of the disposition of these elements over the 

 entire cortex of a series of human and anthropoid apes' brains constitutes 

 the groundwork of the research ; but, in addition to this, pathological 

 material has been employed to amplify and confirm points concerning 

 the topographic distribution of special areas, suggested in the first 

 place by the normal arrangement. 



II. General Histological Considerations. 



After some general explanatory remarks on medullated fibre arrange- 

 ment and cell lamination, each definable cortical area is discussed in. 

 turn. 



III. TJie Pre-central or Motor Area. 



The pre-central or motor type of cortex is confined roughly speaking 

 to the pre-ceritral or ascending frontal convolution and a small coter- 

 minous portion of the paracentral lobule, its distinctive histological 

 characters are a wealth of nerve fibres far superior to that of any 

 other part of the cerebral cortex, and the presence of the " giant cells " 

 of Betz or "ganglionic cells" of Bevan Lewis. It is important 

 to notice that its structure differs absolutely from that of the post- 

 central or ascending parietal gyrus. 



On examining the brains of two chimpanzees and one orang it was 

 found that a similar area could be mapped out, not only agreeing 

 closely in point of structure and distribution with that in the human. 



