2 ORIGINAL ARTICLES 



one stage of our knowledge, were supposed to possess merely 

 nerve fibres which, when they underwent secondary degenera- 

 tion, always did so in an ascending direction (i.e. on the cerebral 

 side of the lesion producing the degeneration). It was also 

 supposed that the posterior columns only conveyed afferent 

 impulses (i.e. nervous impulses, passing upwards towards the 

 brain). 



The first to show that this supposed simple arrangement was 

 not the true one was Dr Charlton Bastian (1), who as early as 

 1867 figured a small descending tract in the posterior columns 

 of the spinal cord which had degenerated in man after an injury 

 to the cervical region. 1 



About 1876, Flechsig (2) showed by the embryological method, 

 of which he has been so great an exponent, that a small area 

 named by him the oval field could be mapped out on either 

 side of the middle line in the lumbar region of the spinal cord, 

 and that these fibres degenerated in the opposite direction to 

 those around them. In 1880, Kahler and Pick (3), Striimpell 

 (4), and Westphal (5), all published cases which, as a result of 

 compression more or less complete at various levels of the spinal 

 cord, produced descending secondary degeneration in the posterior 

 columns ; and three years later, Schiiltze (6) published similar 

 cases showing the same appearances, and particularly pointed 

 out the presence of a comma-shaped tract, which degenerated 

 downwards as a result of compression of the spinal cord in the 

 cervical region. This tract, larger anteriorly, more pointed 

 posteriorly, he described as extending in the posterior external 

 columns for a distance downwards of two and a half centimetres. 

 But as will be seen below, the tract is much more extensive 

 than Schiiltze at that time supposed. 



In 1889, Howard Tooth (7) found the so-called comma tract 

 (in a case of spinal compression) degenerated from the eighth 

 cervical segment down to the eighth dorsal ; and in another 

 case from the seventh cervical to the seventh dorsal segment. 



Schmaus (8) in the same year published a somewhat similar 

 case, and Pfeiffer (9) in 1891 described descending degeneration 

 in the postero-median as well as in the postero-external columns, 



1 It is well known that in many animals, i.e. the rat, mouse, guinea-pig, squirrel, 

 kangaroo, etc., the pyramidal tracts descend in the posterior columns, but animals 

 with such an arrangement are not, of course, considered in this communication. 



