58 
MR. W. BE VAN LEWIS ON THE COMPARATIVE 
Dimensions of ganglionic cells in tlie Ocelot, from sections taken across the 
crucial sulcus. 
Limbic boundary. 
Parietal boundary. 
r I s - 
/<- n 
Upper third. 
Average . 
. . 46 X 20 
48 X 27 
Largest . 
. . 88 X 27 
93 X 32 
Middle third. 
Average . 
. . 51 X 23 
48 X 22 
Largest . 
. . 92 X 27 
93 X 41 
Lower third. 
Average . 
. . 64 X 29 
49 X 27 
Largest . 
. . 92 X 46 
92 X 41 
The Cat (figs. 5, 6, 7).-—The nested cells extending through the faintly-shaded 
portion of the Sylvian convolution can bear no comparison, either in size or number, to 
those seen in the limbic lobe. Throughout the whole limbic boundary of the crucial 
sulcus the ganglionic cells attain such great dimensions, and are so densely grouped, 
that they form quite a characteristic area ; whilst still greater cells of comparatively 
gigantic dimensions, although in smaller numbers, occupy the parietal boundary of the 
same sulcus. The obliquity which the crucial sulcus presents on its deep aspects 
affords a larger area for distribution than would be imagined from a superficial view of 
the hemisphere. The faintly-shaded parietal and frontal convolution represents the 
less richly-developed areas of this formation, but the regions above described we 
should regard as endowed with the higher manifestations of functional activity. 
The Sheep and Pig (figs. 3, 4).—The distribution is so similar in these two animals 
that a separate description is not required. In the diagram it will be seen that all 
portions of the five-laminated cortex are equally shaded, to indicate that, in size of 
cell and complex relationships, the nested ganglionic layer differs but slightly through 
this wide area. That slight differences in size between the cells do occur has already 
been indicated, but we fail to discover over this extensive field the extraordinary diver¬ 
gence in these particulars which is presented by the five-laminated cortex of Man, 
the Ape, and members of the Carnivora. The chief features of interest connected with 
regional distribution in the brains of these animals appear to be— 
1. The wide area of distribution occupied by the five-laminated cortex. 
2. The great uniformity observed in the dimensions and complex relationships of the 
ganglionic cells. 
Divergence in type of Ganglionic Cell. 
In close connexion with the subject just considered are the following points, to 
which I am anxious to draw attention. It has been shown that the cells of the 
ganglionic series in the higher development of the motor cortex are larger in Man, the 
