( 19 ) 



nahhlt 16. Nov. 16^'', J9(U). 



It seems a /priori probable thai the extirj)alioii ol' a part of Ihe 

 neocortex will cause in the opposite heniisi)here changes of the same 

 nature as are bronglit about l)y section of the corpus callosum. lu 

 order to verify this presuni|)tion tlie frontal (piarter of the lateral 

 wall of the right hemisphere was extirpated, including the region, 

 slight faradic stimulation of which caused movements on the crossed 

 side (facialis and jaw ; the fore-leg reacted on\y slightly). The i-cgion 

 thus roughly delined was well extirpated (i.e. the knife was inserted 

 a little more distally). After the narcose the left eye-slit was 1.5 mm. 

 larger than the right one; the left fore-foot did not react on an 

 unusual position being given to it (dorsum manus on the ground), 

 while the right fore-foot did so immediately". 



By the next day these symptoms had disappeared. The animal 

 was quite normal and died of enteritis in the night between 10''' 

 and 11^'' December, having thus lived 24 days. The anterior half 

 of the left hemisphere was treated by Nissl's method, when it 

 appeared that the injury was contined to the region described above. 



Owing to the circumstance of the animal having been dead for 

 some hours and having suffered from an infectious disease, some 

 caution must be exercised in judging of the colouring results, and 

 only such as are independent of the more specified reaction of the 

 cells on the colouring matter should be accepted. A few seemingly 

 mistbrmed, badly coloured, or almost colourless cells should not be 

 regarded. Even taking this into account, however, there is never- 

 theless a distinct alteration visible in the tifth layer, which with regard 

 to the nature of the remaining cells does not appear to differ fi-om the 

 conditions in the case of the previous rabbit. 



There are, however, more cells which are well coloured^), and more- 

 over the coloured ones are not confined to the immediate proximity 

 of lamina IV, but also occur, though in less number, on the boundary 

 of the Q^^ layer. 



As was stated above in the case of Cat N". 3, the operator';? 

 knife had come in contact not only with the callosum, but also with 

 the underlying p.snkerium-iibves. The cell changes which would 

 probably be the result of this lesion must be sought for in the 

 ammon's horn. 



There the well-known, large pyramidal cells are indeed altered 

 |)artly in a characteristic way. While a great number of them (on the left 

 side of the arrow in tig. 10) are (piite normal in forui and siructui'e, as 



1) A study of lilt' whole sorios is needed to judge of this. 



2* 



