ANATOMY AND PHYSIOLOGY OF NERVOUS SYSTEM. 



the medulla oblongata these fibers go to form the lemniscus, or fillet, 

 which itself terminates in the corpora quadrigemina, the optic 

 thalami, and the sensory convolutions. In transverse section of this 

 column there is ascending degeneration. 



The comma tract is composed of a few fibers in the column of 

 Burdach. After lesions of the cord they undergo descending degen- 

 eration. These fibers originate from the descending fibers of the 

 posterior roots. 



Fig. 238. Section of Spinal Cord, Showing the Less Well-known Tracts. 



1, Comma tract. 2, Lissauer's tract. 3, Monakow's prepyramidal or rubro- 

 spinal tract from nucleus ruber down lateral column to anterior horn. 4, Ves- 

 tibulo-spinal tract from vestibular nucleus down to anterior horn. 5, Sulco- 

 marginal tract from corpora quad. 6, Anterior marginal bundle from nucleus 

 fastigii. 7, Helweg's bundle from olivary body. 8, Anterior root. 10, Posterior 

 root. 9, Oval bundle. 11, Septo-marginal. 



The posterior columns, and particularly the columns of Burdach, 

 ire the seat of the sclerosis known as tabes dorsalis, or locomotor 

 taxia. Clinically this disease is characterized by progressive aboli- 

 ion of co-ordination, loss of equilibrium, paralysis of eye-muscles, 



of tendon reflexes, etc. 



Tracts of Lissauer. About the entrance, of the posterior roots 

 ito the postero-lateral groove of the cord are found two small. 



