246 Journal of Comparative Neurology. 



through the m. intertransversales, to which it sends numerous 

 fibers. Emerging ventrally of this muscle, it sends fibers to 

 the m. basi-scapularis and continues caudad in the roof of the 

 pharynx. It turns cephalad ventrally of the pharynx, posteri- 

 orly of the t. visceralis and ramus recurrens vagi. In close 

 relation with the latter nerve and with the ventral branch of the 

 second spinal nerve, it lies for some distance along the dorsal 

 surface of the m. sterno-hyoideus. However, upon separation 

 from this nerve it incHnes ventrad along the lateral side of this 

 muscle and, at the transverse level of the glottis, meets the 

 ventral branch of the second spinal nerve again and anastomoses 

 with it. The resulting nerve innervates the m. sterno- 

 hyoideus and m. genio-hyoideus. 



In the adult the anastomoses between the ventral rami of 

 the two spinal nerves takes place immediately as the ramus of 

 the first passes out of the m. intertransversales. In the adult, 

 also, the roots of the first spinal nerve seem to remain distinct 

 in their passage through the foramen, and the axones of the 

 second root seem to enter the ventral ramus. This would indi- 

 cate that the axones of the second root, only, function as 

 hypoglossal nerve. Yet the ventral ramus sends fibers to the 

 m. intertransversales. It is possible that the fibers to this 

 muscle, however, pass from the first into the second root in the 

 passage through the foramen. But even if this distinctness of 

 roots exists, the root which functions as hypoglossal would 

 still arise as a typical spinal root, since the two roots do not 

 differ in this regard. 



After giving off the two rami just described, the first 

 spinal nerve turns dorsad {sp. id.) and bears a small ganglion 

 on its lateral side {g. sp. /). The nerve then divides into two 

 portions, one of which passes dorso-cephalad and the other 

 dorso-caudad into the m. extensor dorsi communis. 



The ganglion of the first spinal nerve gives rise to small 

 meduUated fibers which go out with the dorsal rami, and from 

 these rami fibers may be traced, in one of my series, to the skin 

 of the dorsum. These fibers to the skin must be derived from 



