(6 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
Bruner (:07, p. 47) gives quite a detailed description of the innerva-. 
tion of the striated muscle of the jugular vein in reptiles. He finds — 
this muscle in Lacerta agilis to be innervated by a number of nerve 
twigs which are given off from the rami communicantes internus et 
externus. The latter join the proximal end of the petrosal ganglion, 
of nerve LX, which, in addition to its root is also joined by a communi- 
cating ramus from ganglion X. Bruner applied stitnulation methods 
at various points in this nerve complex and thus determined the path 
of the motor fibers to the “m. constrictor venae jugularis internae”’ 
to be from the brain through the roots and root ganglion of nerve 
X, across to the petrosal ganglion through the communicating ramus 
between IX and X, and then cephalad along the rami communicantes 
internus and externus to points where the “ nervi tumefactores capitis” 
are given off to the adjacent muscle surrounding the jugular vein. 
According to Bruner the function of this musculo-nervous mechanism 
is to contribute to the swelling of the cephalic veins and sinuses of the 
head by blocking the return of blood through the internal jugular vein. 
In Anolis (Fig. K) these “ tumefactor” nerves show closest anatomical 
relations to nerve X, the indirect course described by Bruner being — 
unnecessary because here the constrictor muscle les relatively more — 
caudad than in Lacerta. Notwithstanding the fact that these nerves 
are given off elsewhere, the ramus communicans X et IX occurs 
quite constantly (see Plates 2, 3, absent Fig. K). It is possible, then, 
that this communicating ramus is an efferent sympathetic path not — 
exclusively related to the constrictor muscles of the jugular vein. 
After the union of the superior laryngeal ramus of X with that of | 
pharyngeal [X the combined nerve (phz-lar.) joins XII in its course 
to the ventral side of the pharynx. Beyond this point not all the 
components of IX and X can be followed and accounted for positively : 
in their distribution. It seems certain, however, that the laryngeal — 
branch (phx-lar.’), the first given off from XII after it reaches the ven- — 
tral side (figs. 5, 6), represents a large portion of this nerve, although | 
its smaller size establishes the fact that the trunk of XII still carries | 
some of the fine fibers. By using fine needles in dissection this laryn- | 
geal ramus can be split away from the main trunk of XII and thus it | 
may be demonstrated to represent the larger part of ramus pharyngo- | 
laryngeus, whose union with XII is mentioned above. 
el 
1. RELATIONS BETWEEN NeERvES IX AnD X. 
Preceding an account of the terminal rami of IX and X, a general- 
ized summary of the relations of roots and main trunks of these two - 
