CRANIAL NERVES. 54D 
6. The ‘‘ facial proper,”’ apparently os from 3, 
supplies the muscles of the hyoid arch 
7. The ‘‘chorda tympani,” apparently arising from 3,. 
runs under the spiracle to the inner side of the- 
jaw. 
With the loss of the sensory ampullee, the seventh: 
nerve of higher Vertebrates becomes restricted to: 
the last three branches (5, 6, and 7). 
A recurrent branch of the facial also runs externah 
to the auditory capsule to IX., and is equivalent. 
to Jacobson’s anastomosis in higher forms. 
VIII. The auditory, arising just behind VIL, is the nerve: 
of the ear. 
IX. The glossopharyngeal, the most typical of all, is the 
nerve of the first functional gill-cleft. Its root 
passes through the floor of the auditory capsule, 
and bears a ganglion above the cleft. Its. 
branches, as named by Beard, are :— 
I. Peal to the muscles of the first branchial! 
arch ; 
2. Pree-branchial, arches over the cleft and runs along. 
its front wall; 
3. Intestinal or visceral, to the pharynx ; 
4. Supra-branchial or dorsal, to a few sense organs om 
the mid-dorsal line of the head. 
X. The vagus, apparently made up of several cranial 
nerves, has numerous roots, and divides into six 
main ganglionated portions, which supply the 
four posterior clefts and arches, the posterior 
jelly-tubes, and the heart and stomach. It thus. 
consists of :—~ 
1. Ganglionated roots with nerves to the clefts and’ 
arches (2 to 5 inclusive), with post-branchial, 
pree-branchial, and pharyngeal branches as in IX. 
2. A ganglionated root, arising in front of all the 
others, from which arises the lateral branch 
innervating all the posterior sensory tubes. 
3. From the fourth branchial branch arises the gang- 
lionated intestinal which innervates the heart and 
the stomach. 
The spinal cord lies in the ee neural archwad! 
above the vertebral column, is divided by deep dorsal any 
ventral fissures, and gives off numerous spinal nerves,. 
formed as usual from the union of dorsal (sensory) and 
