ON THE FUNCTIONS OF THE CEREBRAL CORTEX. 
23 
upper part of the trunk, while the lower (paresed) limb has exhibited no diminution 
of sensibility whatever. 
We have performed a few experiments in which we endeavoured completely 
to destroy, upon the same side of the brain in successive operations, both the hippo- 
campal convolution and the gyrus fornicatus, i.e., the whole of the limbic lobe. 
Although we cannot claim to have fully succeeded as yet in this attempt, having been 
foiled by the extreme diflSculty of getting at all portions of this lobe, our results have 
not been devoid of interest. They have tended to show that, while a lesion of either 
the hippocampal gyrus or of the gyrus fornicatus alone produces, as the experiments of 
Ferrier have shown for the former convolution — and our own, just alluded to, for the 
latter — a more or less marked diminution in the power of appreciation of sensory 
impressions applied to the opposite side of the body, the part played by the gyrus 
fornicatus is of greater importance in this respect than that played by the hippo- 
campal convolution and hippocampus. For when even a considerable lesion has been 
made in the hippocampal region the resulting hemiansesthesia is not always very well 
marked and is not long persistent. If, however, this is now followed by an extensive 
lesion of the gyrus fornicatus, the hemiansesthesia is very well marked and long 
persistent. On the other hand, when the operation has first been performed upon the 
gyrus fornicatus, the anaesthetic condition is, as we have seen, very well marked if the 
lesion has been considerable, and persists in a diminished form for an indefinite period. 
And a lesion of the hippocampal region will now produce but little increase of the 
anaesthesia. From which it would appear that, although the whole limbic lobe may 
be concerned in the perception of sensory impressions, the part played by the gyrus 
fornicatus, at least as respects cutaneous sensibility, is more important than that 
played by the hippocampal portion of the lobe. But until it has been possible entirely 
to destroy the whole lobe upon both sides of the brain it is impossible to determine 
whether it is assisted in its function by any other portion of the cerebral cortex.* 
Conclusions and remarks. — The results of our experiments upon the limbic lobe 
seem to point to the conclusion that this portion of the cerebral cortex is largely, if 
not exclusively, concerned in the appreciation of sensations, painful and tactile. This 
is an extension of the view put forward by Ferrier, who was inclined, as the result 
of his own experiments, to limit that function to the hippocampal region. Dr. Ferrier, 
who was good enough to assist at some of our experiments upon this part, has fully 
accepted the conclusions to which they point.t These conclusions appear, however, 
completely incompatible with the views of most of our predecessors in the field of 
experimental cerebral research. Of these predecessors we need now refer only to 
GoLTZ, ScHiFF, and Munk, With reference to the views of Goltz, we may remark 
* It is important here to remark that the possibility of an accidental lesion of the r^scending sensory- 
tracts, which has sometimes been put forward as an objection to the aneesthesia obtained by Ferrier from 
lesions in the hippocampal region, is altogether absent in the case of a lesion of the gyrus fornicatus. 
t ' Functions of the Brain,' 2nd edition, pp. 341 et seq. 
