340 
MR. E. P. FRANCE ON DEGENERATIONS WHICH FOLLOW LESIONS 
Microscopic. Pons .—Scattered degeneration can be seen in the pyramidal bundles 
of both sides. 
Medulla .—Scattered degeneration can he seen in both anterior pyramids. 
Spincd Cord. Cerviccd Region .—The degeneration occupies that part of the 
crossed pyramidal tracts which borders on the direct cerebellar tract, and extends 
from the posterior cornua towards the circumference on both sides. It is not very 
well marked, but occupies a similar position to that of all the other marginal cases. 
Dorsal Region .—In the dorsal region it is relatively less in amount, closer to the 
circumference, and does not extend as far forwards. 
Lumbar Enlargement .—It is much less in amount here, and lies in the angles 
formed by the posterior cornua and the circumference of the cord. 
Case 6.— No. PI of First Series. 
Lesion .—Kemoval of both marginal convolutions at two operations. 
Fronted sections through the brain show that the convolutions were completely 
removed, except a small strip of grey matter at the deepest part of the calloso- 
marginal fissure on the left side. The adjoining external surface was also injured. 
Residt .—The first operation on the left side produced the usual paralysis of the 
opposite hind limb and of the trunk. The second operation (right side) produced 
])aralysis of the trunk and legs of the opposite side, except that the knee and hip can 
be feebly flexed. 
The animal died three months after the first operation. 
Degenerations Observed. 
Very well marked degeneration is visible to the naked eye on both sides in the 
crossed pyramidal tracts. 
J^ons and Medulla .—Under the microscope sections show .scattered degeneration in 
the pyramidal bundles and pyramids. 
Spinal Cord. Cervical Enlargement. — There is degeneration on both sides, 
extending over a large portion of the crossed pyramidal tracts, and involving part ot 
the region of the direct cerebellar tracts. 
The degeneration in the crossed pyramidal tracts is like that observed in the spinal 
cords of the other animals after similar lesions, although more extensive than in most 
cases. The region of the direct cerebellar tract* is also greatly involved on both 
sides. A small triangular patch of healthy fibres represents this tract, close to 
the posterior root exit. 
Dorsal Region .—The degeneration is well marked and rather more defined than in 
the cervical region. The parts in the direct cerebellar tracts noticed to be free from 
degeneration in the cervical region are still seen, and appear rather larger. 
'* Probably the porUon of the pyramiLlal tract which encroaches on the cerebellar tract. 
