willard: cranial nerves of anolis carolinensis. 93 



posterior part of mylo-hyoideus. The mucous membrane covering 

 the tongue and along the inner side of the lower jaw is innervated by 

 somatic sensory and viscero-sensory components, these being mingled 

 in the same rami, the former by way of the lingual branch of mandibu- 

 lar V, the latter through the chorda tympani from VII. The somatic 

 sensory elements appear to be especially well distributed to the long 

 papillae in the glandular subterminal region of the tongue, while the 

 viscero-sensory are associated with regions bearing taste buds and 

 glands along the sides of the tongue and the jaw. 



U. SPINAL NERVES. 



Inasmuch as the anterior spinal nerves have undergone modifica- 

 tion of their typical character due to the same process of cephaliza- 

 tion which has affected the cranial nerves, an account of the first three 

 is included in this paper. The third cervical is the first one that 

 possesses both somatic-motor, and somatic-sensory components typi- 

 cal of a complete spinal nerve. 



1. The third spinal nerve, as might be inferred from the last 

 sentence, is the most anterior spinal nerve to have both ventral and 

 dorsal roots. The two roots and the spinal ganglion lie in nearly the 

 same transverse plane (Plate 7, fig. 24). The dorsal root enters the 

 spinal cord on its dorso-lateral side as one compact strand, coming, 

 within the vertebral canal, from the spinal ganglion, which lies in the 

 large intervertebral foramen at the level of the ventral side of the spinal 

 cord. This foramen is between the second and third cervical verte- 

 brae. It is impossible to analyze these roots further than to indicate 

 the position of their somatic components. The sections do not show 

 visceral components in the distribution of peripheral branches, but 

 since the muscles tend to obstruct the fixation and blackening of the 

 nerve fibers, it is possible that some have escaped observation. The 

 sensory bundles emerge from the ganglion as parts of dorsal and 

 ventral rami, the ventral ramus being about double the diameter of the 

 dorsal. The ventral root, composed of somatic-motor fibers, arises 

 as a number of rootlets passing out from the ventral horn of the cord. 

 This root, while on the median side of the ganglion, splits into dorsal 

 and ventral divisions (Plates 2, 3, figs. 4, 6). The ventral immediately 

 joins the ventral sensory ramus, while the dorsal again divides, dorsal 

 to the ganglion, into a part which joins the dorsal sejisory ramus and a 



