COETEX OF FOEEBEAIN AND MEDULLA OF HBMISPHEEES. 



229 



a section is here shown in Fig. 150 

 accurately reproduced by Nissl from 

 an alcoholic preparation. It may be 

 of good use to you in practical 

 work. 



The medullary rays separate, on 

 reaching the cortex, into numerous 

 fine tracts, and these become gradually 

 lost in the more superficial layers of 

 the cortex; that is to say, become con- 

 nected with the neuraxons of the cells. 

 Besides these tracts, numerous other 

 medullated nerve-fibers are seen in the 

 cortex. Until recently the origin and 

 destination of these fibers were entirely 

 unknown. Lately, howeyer, the in- 

 vestigations by Golgi, Martinotti, and 

 especially by S. Ramon y Cajal, have 

 acquainted us with a great number of 

 new relations in the cerebral cortex; so 

 that it now appears possible to consider 

 the separate elements in their various 

 combinations. It is true, most of the 

 facts have been recognized on the cere- 

 bral cortex of small mammals, and a 

 few only have been confirmed for man. 

 Thus, much work still remains to be 

 done. What is known, however, takes 

 us such a good step forward that I 

 must impart it to you. In order that I 

 might make my description brief, I 

 have represented the most important 

 discoveries combined in a single draw- 

 ing (Fig. 152). 



Fig. 151. — Section through the cortex of a. frontal gyrus. The right half is 

 reproduced from a preparation stained with Weigert's hsematoxylin, the left half 

 from preparations made by Oolgi's sublimate method. On the right the fibers 

 only are to be seen; on the left the cells only. More cells are present than are 

 shown in the drawing. Since the spaces around the cells and their processes 

 are filled by Oolgi's method, these appear to be larger than they really are. 

 Tangentialfasern, Tangential fibers. Superradicires Flechttoerk, Superradial net- 

 work. Oennarischer Streif, Line of Gennari. Interradidres Flechtwerk, Inter- 

 radial net-work. 



