THE HISTOLOGY OF DISSEMINATED SCLEROSIS. 733 



Fig. 243. Third lumbar segment at a low level. Note areas at the tip of the anterior fissure and 

 around posterior median fissure. Also a = peri-central sclerosis, and 6 = area in lateral part of anterior 

 grey matter. 



Fig. 244. Third cervical segment. Note the tendency towards symmetry and the varying stages of the 

 involvement. 



Fig. 245. Junction of seventh and eighth cervical segments, a = small isolated areas. 



Fig. 246. Eighth cervical segment near the junction with first dorsal. Note a = large triangular area 

 with base to surface of the cord — extension to the grey matter which is still outlined. 



Fig. 247. Third lumbar segment, a = symmetry of involvement of the tissue around central canal and 

 adjoining anterior median fissure. 



Fig. 248. Fourth lumbar segment — incomplete symmetry. 



Fig. 249. First sacral segment. Large irregular area with distinct outline. 



Fig. 250, x 10. Frontal longitudinal section of the cord showing complete demyelination. a = normal 

 nerve roots ; b = longitudinal small vessels with condensed walls. 



Figs. 251-252. Upper and lower levels of first dorsal segment — from serial sections. Involvement 

 simulates secondary degeneration. 



Plate LXII. 



Figs. 253-264. Special features of spinal cord areas. Kulschitsky-Pal witli picro-fuchsin. Figs. 253- 

 258 and 260-263, x 30 ; fig. 259, x 40 ; fig. 264, x 80 



Fig. 253 (cf. fig. 241 (a) ). Note a = lateral vessels passing to area which has picked out the postero- 

 lateral group of anterior horn cells ; b = wide glia marginal zone. 



Fig. 254. Small oval area around an artero-lateral vessel. 



Fig. 255. Larger area extending from the anterior surface of the cord to involve the anterior margin of 

 grey matter (a). 



Fig. 256. a = small oval area at junction of white and grey matter, around the terminal branches of a 

 lateral vessel ; b = smaller area near the surface around a lateral vessel. 



Fig. 257. Wedge-shaped area with truncated apex. 



Fig. 258. Small undefined area within the lateral column of white matter. 



Fig. 259. Triangular area in posterior columns with apex near posterior commissure (a). This area 

 extends posteriorly to the surface of the cord. 



Figs. 260-262. Indistinctly outlined, small areas around the anterior, middle, and posterior thirds, 

 respectively, of the posterior median fissure. 



Fig. 263 (cf. fig. 242(a)). Demyelinated glious area in the immediately extra-medullary portion (a) of 

 the posterior root and continuous with large area in the postero-lateral region of the cord (L5). 



Fig. 264. Similar demyelinated glious area (a) immediately external to the " Ablassung " zone (b) ; intra- 

 medullary fibres normal (c). 



Plate LXIII. 



Figs. 265-276. Special features of cerebral areas: figs. 265-268, in the basal ganglia; figs. 269-276, 

 chiefly involving the cortex. Kulschitsky-Pal with picro-fuchsin. 



Fig. 265, x 5. Two areas (a) involving both internal capsule and globus pallidus ; a third area (b) 

 cutting across the internal medullary lamina of the lenticular nucleus and extending into both globus 

 pallidus and putamen. 



Fig. 266, x 13. Area around blood-vessel in the lenticular nucleus. 



Fig. 267, x 6. Areas, around vessels, involving a = optic thalamus; 6 = internal capsule; and c = 

 lenticular nucleus. 



Fig. 268, x 7. Area in the white matter of the occipital lobe in the path of the optic radiations. 



Fig. 269, x 6. Convolutions around the calcarine fissure, showing involvement of the optic radiations 

 (a) and of the cortical grey matter (b). 



Fig. 270, x 6. Convolutions around the opposite calcarine fissure of the same case as fig. 269, 

 showing a large number of areas, a = small area confined to a medullary ray; 6 = areas involving both 



TRANS. ROY. SOC. EDIN., VOL. L, PART III (NO. 18). 101 



