Herrick, Pathology of Goicral Paralysis. 145 



producing degeneration of the latter and finally leads to atrophy 

 and shriveling." 



Mendel suggests that the great diversity in the symptom- 

 ology of general paralysis may be due to the existence of varie- 

 ties with an interstitial and a parenchymatic origin. 



The present case shows sufficiently well that the intensity 

 of the degenerative process varies greatly in various regions. 

 This is sufficient to account for great diversity in the facies of 

 the disease. It would seem that there could be no limit to the 

 range of variation where the slightest change in the seat of dis- 

 turbance might interrupt a different set of channels of commun- 

 ication. -Historically the opinions of the cause of the malady 

 have varied between wide extremes. Meschede, in 1865, con- 

 sidered the alteration in the ganglion cells of primary impor- 

 tance and considered the disease a parenchymatous inflamation. 

 Mangan, in 1866, described it as an interstitial encephalitis, 

 while Rokitansky and, finally, Luys referred the trouble to the 

 neuroglia ; the latter called it diffuse interstitial sclerosis of the 

 neuroglia. 



It is not unnatural that vaso-motor changes should be ap- 

 pealed to as fundamentally important, as has been done by 

 Obersteiner, Thompson and others, in fact it is difficult to see 

 how the undoubted connection between mental strain, on the 

 one hand, and vaso-motor disturbance of alcoholism on the other, 

 with the degenerations of general paralysis is to be explained 

 without admitting, via functional hyperaemia and temporary 

 vaso-moter incordination, the graver and more permanent changes 

 which should make way for morbid nutritive changes in the 

 cells. If metabolism is altered by altered blood pressure it 

 would be natural that other cellular elements besides the cortical 

 cells should be modified. It would seem more rational to sup- 

 pose that all the cellular structures in the region affected should 

 feel the effects of vascular disturbance and react, each after its 

 kind, while reciprocally modifying each other and thus the 

 course of the disease. Instead then of drawing a distinction 

 between interstitial and parenchymatous phases we may 

 restrict ourselves to such practical classification in accordance 



