THE PYRAMIDAL TRACT 



523 



riphery of the cord. The anterior median fissure traversed the 

 field. 



As Draeseke ('04) has pointed out and as seen in figure 5, the 

 tract is nearer the gray substance than the ventral border of the 

 cord. The myelin sheaths are very small in diameter and are 

 sparsely scattered in the field. It is due to marked reduction, 



c.aa 



fm.a 





Fig. 5 From a section taken somewhat below the middle of the cervical 

 portion of the spinal cord of the mole (Scalopus aquaticus). Pal-Weigert. X 93. 

 The pyramidal tract is located in the anterior funiculus and forms a sharply out- 

 lined imstained area. The few medullated fibers which it contains are probably 

 admixtures from other fasciculi of the ventral funiculus. 



or one might say, almost total absence of these sheaths, that the 

 tracts remain colorless in Pal-Weigert preparations. In measur- 

 ing the diameter of these sheaths the largest found in the field 

 measured 4.84 ;u and are probably admixtures of fibers from the 

 other tracts in the ventral funiculus. The rest of the white 

 substance of the cord was stained light blue due to the presence 

 of numerous myelin sheaths and had the appearance, typical 

 of the white substance in other cords. 



