238 



THE DEVELOPMENT OF THE CHICK 



there bifurcates, producing two branches, one of which grows 

 towards the head and the other towards the tail in the dorsal 



Col- 



FIG. 142. Six centripetal axones of the dorsal 

 root, rigorously copied from a good preparation 

 prepared according to the method of Golgi. 

 From a longitudinal and tangential section of 

 the dorsal column of the spinal cord of an 8- 

 day chick. (After Ramon y Cajal.) 

 Col., Collaterals. 1, 2, 3, 4, 5, 6, the axones 



entering the cord. 



column of the white matter. The ascending and descending 

 branches send off lateral branches, collaterals, which pass deeper 

 into the cord, and ramify in the gray matter of the dorsal horn. 



