902 
6. The cardiac branches of the vagus have no 
direct effect in maintaining the movements of the 
heart. Though the movements of the heart 
may be materially influenced by causes acting 
through the vagus, yet mental emotions and 
injuries of the central organs of the nervous 
system affect the heart's action through the 
sympathetic after the vagi and recurrents have 
been divided in the neck. 
7. The pulmonary branches of the vagus con- 
sist chiefly of incident filaments and convey 
impressions, capable of producing respiratory 
juscular movements, made on the inner sur- 
ice of the lungs to the medulla oblongata. 
When the vagi are cut or tied in the neck the 
respirations instantly fall in frequency, and are 
reduced to about one half their former number. 
The existence of motor filaments in these 
branches has not yet been satisfactorily esta- 
blished. 
8. Though excitation of the nervus vagus 
in the neck causes muscular contractions of the 
stomach, yet the muscular movements of the 
stomach are not entirely dependent upon the 
gastric branches of the vagus, and the stomach 
may still propel the chyme into the duodenum 
after the vagi and recurrents have been divided. 
Lesion of the gastric branches of the vagus does 
not necessarily arrest the secretion of the usual 
fluids poured out into the interior of the sto- 
mach, though these are generally changed toa 
considerable extent both in quantity and quality 
by causes acting through the nervous system. 
The rapidity of the absorption of poisonous 
substances from the inner surface of the sto- 
mach is not perceptibly diminished by the 
division of the vagi. 
9. Division or ligature of the vagi in the 
neck is almost always fatal. The cause of 
death, in by far the greater number of cases, is 
congestion of the lungs with blood induced by 
the diminished frequency of the respiratory 
muscular movements. In a few cases the ani- 
mal dies of inanition from derangement of the 
functions of the stomach.* 
(John Reid.) 
PAROTID REGION.—This region (in 
surgical anatomy) is of a somewhat pyramidal 
form, the base corresponding to the surface of 
the skin, and the apex to the pharynx. The 
* The author embraces this opportunity of cor 
recting some of the errors which have been over- 
looked in printing this article. 
P. 882, col. 1,1. 11, for ** cross,” read ‘‘ crosses.” 
= 2, foot note marked }, 1.7, for “ en- 
largement,” read ‘* arrangement.” 
P. 888, col. 2, foot note, 1.17, for ‘* while the 
other two vagi, or,’”’ &c. to the end of the 
sentence, read “‘ while the other two vagi 
give off the left recurrent of the right larynx 
and the right recurrent of the lett, as they 
pass the larynges.” 
P. 890, col. 1, last line, for “‘ that in the,” read 
«« that while in the.” 
P. 890, col. 2, 1. 5, for «* while the recurrent one 
of the motor branches is,” read ‘‘ while 
the recurrent, one of the motor branches, 
is. 
P, 893, col. 1, last line one, for ‘* motor 
filaments,” read ‘* sensiferous filaments.” 
PAROTID REGION. 
superficial boundaries of the region are, supe- 
ale the root of the zygoma and the articu- 
lation of the jaw; inferiorly, a line drawn from 
the angle of the jaw to the anterior borderof the 
sterno-mastoid muscle ; anteriorly, the posterior 
border of the masseter muscle ; and posteriorly, 
the meatus auditorius, the mastoid process 
with the anterior border of the sterno-mastoid 
muscle. 
In the present article it is intended to gis 
the relative anatomy of the parts contained in 
this irregular and ill-defined region. 
Commencing the dissection by removing the 
integument from the parotid region, we 2 
some delicate muscular fibres which constitute 
the upper part of the platysma or the risorius 
Santorini; these fibres, however, are not con- 
stantly present. After removing a fine reti- 
cular tissue, the superficial surface of the pa- 
rotid fuscia is seen. This is a strong fibrous 
fascia which is continuous below with the cer- — 
vical fascia; it passes over the superficial sur- 
faces of the parotid, being attached above to 
the zygoma, and behind to the cartilage of the 
ear, while in front it is thinner and is pro 
over the masseteric region. The fascia also 
dips down into the substance of the gland and 
divides it into lobes and lobules. 
The Parotid Gland, from which the name 
of this region is derived, is the largest of the 
three salivary glands. Its form is irregular, and 
is determined by the surrounding parts into the 
interstices of which it is packed and moulded. 
Relations of the parotid—A description ¢ 
the relations of the parotid gland will include 
the greater part of the relative anatomy of the 
parotid region. The external surface or base 
of the gland corresponds to the skin; it is of a 
somewhat irregular quadrilateral form, and its 
boundaries are identical with those of the pa- 
rotid region, except that a portion of the gland 
the socia parotidis, is prolonged forwards wit 
the duct over the masseter muscle. The anterio 
surface of the parotid is grooved to receive the 
posterior border of the ramus of the jaw; | 
also corresponds to the internal pteryge 
muscle, the stylo-maxillary ligament, and # 
masseter muscle, upon the external surface 
which it is prolonged, but from it | 
some loose cellular tissue, by branches of t 
portio dura nerve, and by the transverse fac 
artery. The posterior surface correspot 
to the cartilaginous portion of the exter 
meatus, upon the convexity of which it 
moulded, and to which it is connected 
dense cellular tissue; this surface is also rek 
to the mastoid process and to the sterno-n 
toid and digastric muscles. It is related § 
riorly to the zygoma and the tempero-maxi 
articulation ; inferiorly it fills up the space 
tween the angle of the jaw and the an 
border of the sterno-mastoid muscle. It 
comes into relation with the submaxillary g 
but is separated from it by the stylo-m: 
ligament. The internal or deep surface of t 
parotid is very uneven; it fills up the posteri 
part of the glenoid cavity and the space bi 
tween the ear and ramus of the re 
rounds the styloid process and I 
