62 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
: 
of the dentary bone, which carries the nerve. Through this opening : 
into its cavity the tooth receives its nerve and blood supply. The — 
innervation was not determined for the posterior teeth, the first fibers 
given off from the alveolar nerve being farther forward, where a small — 
number (3 or 4) of fibers with distinct sheaths come off from the main 
ramus and run forward within the alveolar cavity for some distance, 
but eventually pass into the cavities of the teeth (Plate 4, fig. 9, 
rm. de.). Where these fibers are given off they show a character 
similar to the cutaneous sensory components, although they either 
become less heavily myelinated or, what is more likely, their position 
makes fixation defective, for they can with difficulty be traced through 
the communication into the pulp cavity of the tooth. It is not 
improbable that here they do lose their myelin sheaths. It is notice- 
able in the mature teeth that the dentinal tubules are particularly 
large at the apex of the teeth. No nerve fibers could be followed, 
however, as far as the odontoblasts underlying this region. 
This\alveolar ramus is described by Watkinson (:06, p. 462) as 
innervating the teeth through the “rami dentales.”’ Such rami in 
Anolis would consist of a few fibers given off at wide intervals, which 
would be difficult to discover except by microscopic methods, even 
though they were not entirely within the bony part of the jaw. Norris 
(:08, p. 522) referred the innervation of the teeth in Amphiuma to a 
combined V and VII nerve which runs along the median side of the 
mandible. This nerve corresponds to the main part of the chorda 
tympani in Anolis, which after temporary union with the mandibular 
nerve has separated from it, reappearing with a mixture of cutaneous 
components, which are distributed with it. Although many fine 
fibers pass from this nerve along the base of the teeth to the epithelium 
of the lingual gums, no connection was established with the teeth 
themselves. 
N. FACIAL NERVE. 
The roots of the facial nerve. Two roots can be demonstrated for 
nerve VII, a lateral (motor) one and a dorsal (sensory) one. The 
sensory passes out directly from the fasciculus solitarius (Plate 6, 
fig. 18, re. VII) as a strong bundle to emerge from the brain dorsal to, ” 
but in contact with, the root of VIII. It passes around the anterior 
side of this root, being entirely covered laterally by the large acousti¢ 
ganglion. On the ventral side of the root of VIII the sensory root of | 
