264 S. WALTER RANSON 



kinds of medullated fibers in the tract of Lissauer: (1) fibers from 

 Flechsig's ground bundle ; (2) fibers which unite the posterior and 

 lateral funiculi at the same level; (3) fibers out of the substantia 

 gelatinosa which after a short course enter the gray substance 

 again; (4) in man and many animals there are horizontal fibers 

 which come from the dorsal roots and cross the tract of Lissauer 

 to enter the substantia gelatinosa. In his opinion the dorsal 

 roots contribute practically nothing to the vertical fibers of the 

 tract. 



This seems to be borne out, in part at least, by experimental 

 and pathological data. There are a large number of papers, deal- 

 ing with the course of the dorsal root fibers within the spinal 

 cord, based on a study of Marchi preparations of the cord after 

 lesions of the dorsal roots. Human cords, in which extensive 

 degeneration of the dorsal roots has resulted from tumors, syphi- 

 lis and other causes, have been studied as well as the cords of 

 animals in which the roots have been divided. Most of these 

 papers, although describing extensive degeneration in the pos- 

 terior funiculus, make no mention of any degeneration in the 

 tract of Lissauer. (See the papers of Darkschewitsch '96, Frolich 

 '04, Kopczynski '06, Margulies '96, Orr '06, Wallenberg '98 and 

 Zappert '98.) 



Nageotte ('03) states that the tract of Lissauer is composed of 

 fine medullated fibers of endogenous origin. He maintains that 

 they can not be derived from the dorsal roots, because in a case 

 reported by him, in which a tumor involved all the spinal roots 

 in the cauda equina up to and including the fourth lumbar, the 

 fine fibers of the tract of Lissauer were intact. The presence of 

 these intact fibers in this case shows conclusively that many, 

 perhaps a majority, of the fine vertical medullated fibers of this 

 tract are of endogenous origin. It can not be taken as conclu- 

 sive proof that none of the fibers in this tract are derived from 

 the dorsal roots. 



Laignel-Lavastine ('08) studied the spinal cord in a case of 

 syphilis involving the cauda equina. The Marchi stain showed 

 a very few degenerating fibers in Lissauer's tract, and the Weigert 

 stain showed the vast majority of the fibers in this tract to be 



