Henry L. Bruner D1 
into the median part of the constrictor muscle. It supplies the dorsal 
fibers of the muscle. 
The number and origin of the nervi tumefactores capitis are variable 
in different specimens and even on opposite sides of the head in the same 
individual. In one specimen the nerves of one side seem to spring wholly 
from the pars ventralis of the ramus communicans n. glossopharyngei 
cum n. maxillari. In the same specimen on the other side of the head, 
the nerves arise partly from the pars ventralis, partly from the ramus 
communicans internus n. glossopharyngei cum n. facial. In a second 
individual the tumefactor nerves spring from the pars ventralis and 
from the ramus communicans externus n. glossopharyngei cum n. faciali. 
Other variations would doubtless be found in other specimens. 
The origin and path of the tumefactor nerves, as described above, has 
been determined entirely by a study of sections. The course of the fibers 
-which compose the nerves has been further worked out experimentally as 
follows (compare Fig. 7) : 
(a) The fibers of the tumefactor nerves come from a posterior direc- 
tion and not from the anterior part of the ramus communicans n. glos- 
sopharyngei cum n. maxillari. Proof of this fact was furnished both by 
the microscope and by experiment. Cutting of the ramus communicans 
n. glossopharyngeil cum n. maxillari on top of the head in the living ani- 
mal did not interfere with the natural contraction of the constrictor 
muscle one or two hours after the operation. Stimulation of the pos- 
terior end of the cut nerve had no effect on the muscle. 
(b) The fibers of the nervi tumefactores pass through the ganglion 
glossopharyngei. In order to obtain positive evidence on this point a 
specimen of Lacerta muralis was etherized, parts of the skin and super- 
ficial muscles (cucullaris, capiti-mandibularis, episterno-cleido-mastoi- 
deus) were removed so as to expose the constrictor muscle and the adja- 
cent cranial nerves. Stimulation of the ganglion glossopharyngei (1X¢., 
Text Fig. 7) under a lens resulted in strong contraction of the m. con- 
strictor vene jugularis interne. 
(c) The fibers which supply the constrictor muscle come from the 
ganglion radicis vagi (ganglion superius vagi of authors). Negative 
results were obtained by stimulating both the glossopharyngeus and the 
hypoglossus. Stimulation of the ganglion radicis vagi (Xg., Text Fig. 
7), on the other hand, gave contraction of the constrictor muscle. From 
this ganglion the fibers of the tumefactor nerves pass neither through 
the vagus nor accessorius, but through the ramus communicans nh. vagi 
