618 



PHYSIOLOGY. 



the brain,, the anterior pyramid of the medulla and the same side 

 of the corresponding half of the spinal cord. Yet, having arrived 

 in the cord, some of its fibers cross to the opposite side along the path 

 of the white commissure. They finally terminate in the cells of the 

 anterior cornua. This bundle usually terminates about the second 

 lumbar nerve. It undergoes descending degeneration. 



The antero-lateral ground-bundle (root-bundle of the anterior 

 column) occupies the territory between the preceding and the antero- 

 lateral groove. It is formed in part by the anterior roots which 



C.T. 



Fig. 237. Transverse Section of the Spinal Cord. 



T. D., Burdach's tract. T. O., Goll's tract. T. P. C., Crossed pyramidal 

 tract. T. C. D., Direct cerebellar tract. G. T.. Gowcr's tract. T. P. D., Direct 

 pyramidal tract, or Turck's. T. L. P., Deep lateral tract. Straight lines are 

 motor tracts. Little crosses are sensory tracts. Dotted spaces are cerebellar 

 tracts. T. I., T. R., Root tracts. 



descend in a certain course within its interior; but especially by the 

 more or less long, longitudinal fibers. The latter unite between 

 themselves the successive levels of the anterior herns. It is thus in 

 part a system of longitudinal commissural fibers. 



The anterior ground-bundle is continued beneath the floor of the 

 fourth ventricle in the superior longitudinal bundle, and ends in 

 the gray matter of the third ventricle, giving off collaterals to the 

 nuclei of the oculo-motor, pathetic, and abducent. 



Lateral Column. The lateral column is bounded between the 

 line of implantation of the anterior roots and the line of insertion 





