v SPINAL COED AND NEEVES 331 



capable of profoundly modifying the nutritive condition of other 

 tissues, from which it has been attempted to build up the theory 

 of the existence of a special category of nerves, with the function 

 of directly regulating the metabolism and nutrition of the tissues, 

 the so-called trophic nerves. We must examine the data before 

 testing the theoretical value of the conclusions based on them. 



According to Longet, Mayo (1823) was one of the first who 

 called attention to the fact that after lesions of the trigeminal 

 nerve the conjunctiva of the eye becomes inflamed, the cornea 

 ulcerated, and the face on the side of the lesion oedematous. 

 Similar clinical observations were made by other observers. First 

 Fodera, then Magendie and Longet, reproduced these changes 

 experimentally on rabbits, by intercranial section of the trigeminus 

 with a special hooked knife. In addition to panophthalmitis 

 Bernard, Biitner, and Eollet subsequently noted ulcerations of the 

 lips and buccal cavity. 



Magendie (1824) observed that when the section was made 

 above the Gasserian ganglion, the dystrophic changes in the eye 

 set in more slowly or were entirely absent, while they inevitably 

 appeared if the lesion involved the ganglion. Bernard (1868) 

 confirmed these results from his clinical observations. Longet 

 attributed the alterations in the eye after lesions of the Gasserian 

 ganglion to the simultaneous injury to the sympathetic filaments 

 that pass from the carotid branch of the superior cervical ganglion 

 to the Gasserian ganglion, but Bernard does not support this view. 

 In his opinion the extirpation of the superior cervical ganglion 

 delays the trophic disturbances in the eye after section of the 

 trigeminus, by increasing the circulation and augmenting the 

 vitality of the eye and its resistance to the post-operative causes 

 of the dystrophy. 



Sinitzin's experiments (1871) confirmed and extended those 

 of Bernard. On piercing with a glass thread the cornea of a rabbit 

 in which the superior cervical ganglion had previously been ex- 

 tirpated, there was usually no inflammatory reaction ; whereas 

 the same operation performed on the other eye caused extensive 

 conjunctivitis with iritis, and sometimes panophthalmitis. Section 

 of the trigeminus produced no corneal ulceration when the superior 

 cervical ganglion had been destroyed shortly before or immediately 

 after. Lastly, the eye troubles caused by section of the trigeminus 

 rapidly cleared up it the ganglion was excised. 



These results, contradicted by Eckhard and by Senftlebeu 

 (1873), were confirmed by Spallitta in Marcacci's laboratory (1894) 

 by some successful experiments on dogs, which he sums up as 

 follows : 



() Lesions of the Gasserian ganglion constantly induce the 

 trophic lesions of the eye already described by Fodera and 

 Magendie and confirmed by later observers. 



