80 



On the Causation of Diphtheritic Paralysis. [Mar. 17, 



becomes ruptured, the nerve fibre below the point undergoes the 

 Wallerian degeneration. The early stage of the segmental degenera- 

 tion is the breaking up of the white substance of Schwann. 



There may be more than one degenerated segment in the nerve 

 which may then undergo completely the Wallerian degeneration. 

 Above the degenerated segment the nerve is normal, the change 

 being simply peripheral and not central in origin. 



All nerves in the body may be affected by this degeneration: the 

 motor nerves, the sensory, and the visceral (sympathetic). 



An example may be quoted to show the extent of the nerve change. 

 A rabbit, which received two doses, equal to 0*1 gram per kilo, of 

 body weight, showed definite palsy on the twentieth day, and was 

 killed on the twenty-fourth. 



Segmental degeneration was found in the following nerves : — 



I. Motor. 

 Of leg. 



Nerve to sartorius. 

 „ vastus. 



semimembranosus. 

 ,, semitendinosus. 

 „ biceps. 

 ,, gastrocnemius. 

 Of arm. 

 Nerve to pectorales. 

 ,, triceps. 

 ,, biceps. 

 „ flexor of forearm. 

 Of diaphragm. 



Phrenic. 

 Of laryngeal muscles. 



Left recurrent laryngeal. 

 Of psoas. 

 Of eye muscles. 



Branches of third cranial nerve. 



II. Sensory Nerves. 



Long saphenous nerve. 

 Cutaneous thoracic nerve. 



III. Visceral. 



The lower part of right cervical sympathetic. 



The nerve change is, therefore, widely spread over the body. 



Physiological Action of Organic Acid. — This is much less toxic than 

 the albumoses, and I have not succeeded in producing paralysis with 

 it. It, however, produces a moderate degree of nerve degeneration 

 when injected into the circulation. 



