LESION OF DIFFERENT REGIONS OF THE CEREBRAL HEMISPHERES. 517 
of the foot of the right crus was only half the diameter of the left, and stained more 
deeply with carmine—characteristic of sclerosis. The outer portion of the foot of the 
crus was however equal on both sides. Similar sections through the pons (fig. 48) 
showed the same relative reduction and sclerosis of the right pyramidal tracts. 
(The figures are microphotographs of sections magnified about 8 diameters.) 
In the spinal cord the secondary degeneration was still more striking. Sections 
through the cervical, dorsal, and lumbar regions (figs. 49, 50, 51) showed an extra¬ 
ordinary reduction and distortion of the left antero-lateral column. This was due 
to atrophy and contraction of the pyramidal tract or posterior part of the lateral 
column, from which the nerve-fibres had almost entirely disappeared, their place being 
taken by connective tissue staining deeply with carmine. The contraction had 
drawn the posterior horn to the left and forwards—particularly well seen in the 
dorsal region—and had so pulled upon the posterior column as to cause perceptible 
separation of the column of Burdach from the column of Goll. This is marked by a 
fissure visible in all the sections on the left, but not on the right side, or only very 
faintly. Though the left posterior column was distorted, its area was not reduced, as 
may be seen by examination of the sections. 
Remarks .— This case shows that a destructive lesion implicating the cortex of the 
upper half of the ascending frontal and corresponding portion of the ascending parietal 
convolution causes marked and permanent impairment of voluntary motor power in 
the opposite limbs, the face being unaffected. 
The sensibility of the paralysed limbs remained acute and to all appearance 
unimpaired. 
The paralysed limbs, especially the leg which was most affected, exhibited in course 
of time the late rigidity or contracture with exaggeration of the tendon reactions, 
which is so characteristic of hemiplegia with descending sclerosis of the pyramidal 
tracts in man. 
The sclerosis of the pyramidal tracts was in this case unusually well pronounced as 
far as the lumbar region of the cord. This was doubtless due to the long period that 
had elapsed since the establishment of the lesion—more than a year and a half. 
Hence the great shrinking of the degenerated tracts and consequent distortion 
of the spinal cord seen in the sections. It is further noteworthy that though in this 
case there was also an extensive lesion in the left hemisphere, but not in the motor 
area, no secondary degeneration existed on the right side of the spinal cord. 
Experiment 18* (Plate 25, figs. 52-55). 
In this case the left hemisphere was exposed in the region of the fissure of 
Rolando, and the ascending frontal and bases of the three frontal convolutions, and 
ascending parietal convolution were destroyed by the galvanic cautery as far as could 
