Apart tVoni the dilFerence of all the lajers from those in figure 

 8 (the corresponding section of the brain operated upon) which is 

 due to a somewhat horizontally inclined plane of cutting, it is 

 clear tliat in both preparations laminae I to \V do not show any 

 considerable divergences. The nerve cells of the third layer are 

 well shaped, their dendrites can often be easily traced to the 

 periphery. The so-called granular cells of the 4th. layer are of the 

 common, above-described character; I was not able to detect in 

 either of these laminae an unusual nnmber or position of glia-elements. 



The infra-granular pyramidal cells of the 5''' layer in tig. 8, on 

 the contrary, appear to have undergone inij)ortant alterations. Theii- 

 number is decidedly smaller than in tig. 7. The elements themselves have, 

 for the greater part, lost their ordinary shapes and seem to be absolutely 

 structureless clumps of protoplasm. Tiie confirmation of the pathological 

 value of this anatomical finding is given by the compai-ison with the well- 

 shaped nerve cells of the 3'^' layer. (Iliaproliferation does not seem 

 to be present; nor do the preparations permit exactly of demon- 

 strating changes in the intracellular position of nuclei. Exce})t in 

 three or four of the infragranular pyi-amidal cells, the normally 

 visible peripheral dendrite has not been coloured. 



The question whether these changes are of a temporary nature 

 or not cannot be decided ; in any case, according to my experience 

 gained in other experiments, the first alternative is for a number of 

 the injured cells the most probable. In lamina VI, which is almost 

 entirely represented in fig. 8, I could not state changes with suffi- 

 cient certainty. 



The above-mentioned peculiarity of the so-called motor area (zone 

 4 Brodmanïsj with regard to its lamination, makes a conclusion on 

 cell-changes, and especially on a loss of cells in this region difficult. 

 Practically it is impossible to discern the "giganto-pyramides" of the 

 rabbit from the other cells of the same size and shape, which are 

 scattered among them. Up till now I have not succeeded in keeping 

 rabbits alive long enough after the section of the bulbar pyramid, which 

 would cause the more or less complete degeneration of the "giganto- 

 pyramid" cells. The sagittal division of the corpus callosum having possibly 

 brought to degeneration other elements in the same area would, by a 

 comparison with the results obtained from the first-mentioned operation, 

 permit an exact indication of the cells connected with callosal fibres 

 exclusively. Hitherto I have not been able to draw any conclusion 

 beyond the statement that the pyramidal cells in toto have appa- 

 rently decreased in number. 



