156 Journal of Comparative Neurology. 



Sections have been made from the most caudal part of the 

 occipital lobe and show that, as usual, the purely sensory regions 

 are not implicated. The cortex is almost wholly unaltered and, 

 whereas the sections in the motor regions stained slowly and 

 imperfectly with ordinary reagents, here the stain is well differ- 

 entiated and uniformly operative. 



THE BASAL REGIONS. 



The histological changes of general paralysis are typically, 

 if not exclusively, those of the cortex, and particularly of its 

 cells. The references to the degenerative effects in the great 

 ganglia of the axial portion of the brain are, so far as my obser- 

 vation has gone, very scanty. Mendel says: "Aside from the 

 described changes, which occur chiefly in the cortex and adja- 

 cent parts of the white substance, which may, however, occur, 

 though to much less extent, in the large ganglia (an atrophic con- 

 dition is here developed only after paralysis of long duration 

 and extensive laming), there may be observed the greatest va- 

 riety of focal lesions in paralytics." 



The peduncles have been found to be degenerated in a few 

 cases (Huguenin), in one case the gray degeneration of the dor- 

 sal fasciculi could be traced from thalamus to the cauda equina 

 and in the motor peduncles and pyramids, extended to the 

 oculomotor region. 



A section through the very cephalic portion of the thala- 

 mus shows that its small cells are but slightly affected while the 

 somewhat larger multipolar cells scattered in the striatum at the 

 same level are thoroughly implicated. Passing caudad, the thal- 

 amus retains the same general character though increasing to 

 form a large quandrangular area {Fig. i a, Plate D.). Around 

 the margins, near the peduncular fibres there are small multipolar 

 cells which are greatly altered. These cells are like those fig- 

 ured on Plate D, figure 5, which are from x in Fig. i of the 

 same plate. They are larger than the cells of the thalamus 

 proper. 



For a study of the striatum we may select a portion of a 

 section corresponding to "B" of the Pitres-Nothnagel's series 



