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The Cephalic Veins and Sinuses of Reptiles 
6 
cum n. glossopharyngeo, a short nerve (r. c. v., Text Figs. 2 and 7), 
which runs directly from the ganglion radicis vagi to the ganglion glos- 
sopharyngei. Direct stimulation of this nerve caused contraction of the 
constrictor muscle. Stimulation of the ganglion radicis vagi after cut- 
ting this nerve gave a negative result. 
These different tests were repeated with different specimens, both of 
Lacerta murals and Sceloporus undulatus. They show that the fibers 
which innervate the constrictor muscle must be referred back to the 
ganglion radicis vagi, whence they run through the ramus communicans 
n. vagi cum n. glossopharyngeo to the ganghon glossopharyngei. From 
this ganglion, in Lacerta agilis, the fibers continue forward, usually in a 
single bundle, which passes through the ramus communicans internus n. 
glossopharyngei cum n. faciah. From the latter the tumefactor fibers 
pass to the constrictor muscle either directly or through the pars ven- 
tralis of the ramus communicans n. glossopharyngel cum n. maxillari. 
In some cases the fibers of the tumefactor nerves leave the ganghon 
glossopharyngei in two bundles, one of which follows the path just de- 
scribed, while the other enters the ramus communicans externus 0. 
glossopharyngei cum n. faciali. , 
In the course of these experiments on Lacerta and Sceloporus it was 
observed that the constrictor muscle could be stimulated in a reflex way 
through the spinal nerves of the neck. The passage of the impulse 
through the ganglion radicis vagi was indicated by division of the ramus 
communicans n. vagi cum n. glossopharyngeo, after which stimulation 
of the spinal nerves gave no response. An apparently reflex contraction 
of the constrictor muscle has also been observed after stimulation of 
sensory nerves in ‘various parts of the head. It is not improbable, there- 
fore, that under natural conditions the contraction of the constrictor 
muscle may be a more or less reflex act due to stimulation of sensory 
nerves. 
I do not attempt to determine whether the nervi tumefactores capitis 
belong to the vagus or to the accessorius nerve trunk, as in the present 
state of our knowledge it is impossible to draw a hne between these 
nerves. The following facts, however, seem to indicate an origin from 
the so-called vagus portion of the vago-accessorius complex : 
In Cistudo carolina the fibers which innervate the constrictor muscle 
come from the anterior roots of the vago-accessorius series—roots which 
° According to Hoffmann, go, page 745, the ramus communicans nervi vagi 
cum n. glossopharyngeo also contains the fibers of the n. laryngeus superior 
