G. H. MONRAD-KROHN. 



M.-N. Kl. 



joint — at the peroneal nerve where it curves round the fibula — at the 

 great auricular nerve where it rides over the sternocleidomastoid muscle. 

 It seems as if the factors that decide the diminished resistance at these 

 places are chiefly of a mechanical nature. Particularly at these places the 

 nerves are generally felt to be greatly thickened. 



As regards the histological nature of the neuritis, it can already be 

 inferred from the great thickening of the nerve trunks just mentioned 



Fig. I. Dehio's diagram of ascending neuritis (slightly modified). 



As the neuritis ascends from the primary cutaneous patch (I. p.) in the direction of the 



arrow along a mixed nerve, the nerve supply of the muscles (mj^ & m2) and of other areas 



of the skin (S. a. a.) will be cut off, thus causing localised paralysis and anæsthesia also 



outside the primarily' affected patch (secondary anæsthetic area — s. a. a.). 



that interstitial alterations play a great rôle. Parenchymatous changes are 

 however also constantly found, and there is no fixed relation between the 

 intensity of the parenchymatous and the interstitial changes — nor is there 

 a fixed relation between the number of bacilli found and the reaction of 

 the tissue. Lengthy discussions have therefore taken place about the direct 

 bacillary or secondary toxic origin of the neuritis, and about the primary 

 interstitial (with secondary degeneration of nerve fibres) or the primary 

 parenchymatous nature of the neuritis (with secondary interstitial reaction). 

 In considering these questions (which cannot yet be answered with 

 certainty) we have to keep in mind the following facts: 



