350 
MR. E. P. FRANCE ON DEGENERATIONS WHICH FOLLOW LESIONS 
B.—Four cases of removal of the entire motor surface from one hemisphere in 
monkeys. 
The symptoms observed during life, and the degeneration found after death 
were almost exactly alike in all these cases; but in the two which only lived 
one week the degeneration was not so easy to follow out as in the other two. 
These animals lived for periods varying from one week to five months after 
the operation."^ 
Degeneixt tions Ohserved. 
In the internal capsule the degeneration is similar to that following lesions of the 
external motor cortex, but in addition to this, the inner side of the capsule is 
degenerated. 
In the crusta and pons but little difierence can be made out, the degeneration in 
the pyramidal tract being, perhaps, somewhat more complete. 
In the medulla the pyramid of the same side is entirely degenerated. 
In the spinal cord the whole crossed pyramidal tract is degenerated, the part 
bordering on the direct cerebellar tract as completely as the rest. The degeneration 
gradually diminishes as it descends, but can still be seen at the level of the 3rd and 
4th lumbar nerves. 
Summary of Results obtained by the Study of Degeneration following Lesions of the 
Motor Cortical Area. 
Bemoval of the grey matter of the motor area of the brain, exclusive of the 
marginal gyrus, produces degeneration which becomes collected in the internal 
capsule, and tlienee downwards follows a regular and definite course as has already 
been abundantly shown by previous observers. 
-OiagTam 1, 
Hoi'izonfcal section through one hemisphere showing the position of degeneration in the internal capsule 
following removal of the external motor surface (exclusive of gyrus marginalis). 
In the internal capsule, as seen in a horizontal section, it occupies the middle third 
extending farther behind the knee than in front (diagr. 1), but quite distinct for a short 
distance in front of the knee. The deo;eneration does not involve the whole breadth 
of the internal capsule, but leaves the inner border almost entirely free. 
* For an account of the symptoms observed during life and the exact extent of cerebral surface 
removed, see “ A Reco-rd of Experiments upon the Functions of the Cerebral Cortex,” Zee. cit., Cases 15, 
IG, 17, and IS, 
