THE SALIVARY GLANDS. 1 
By J. 1ST. Langley. 
Contents : — Anatomical Characters, p. 475 — Histological Characters, p. 477 — Origin 
and Course of Nerves, p. 479— Changes during Secretion, p. 485 — Reflex Secre- 
tion, p. 489 — The Dyspnceic Secretion, p. 493— Stimulation of the Cranial 
Nerve, p. 493— Stimulation of the Sympathetic Nerve ; the Augmented Secre- 
tion, p. 494 — Effect of Protracted Stimulation on the Amount and Percentage 
Composition of Saliva, p. 498— Relation of the Rate of Secretion to the Per- 
centage Composition of Saliva, p. 499 — Some General Characters of Saliva, p. 501 
—Substances secreted in Saliva, p. 503 — Effects of the Cranial and Sympathetic 
Nerves upon the Blood Flow, p. 504 — Mutual Effects of the Cranial and Sym- 
pathetic Nerves upon Secretion, p. 506 — Effect of Variations in the Amount 
and Quality of the Blood supplied to a Gland, p. 508 — Relation of Secretion to 
the Flow of Lymph, p. 510— The Secretory Pressure, p. 511— Reflex Inhibition 
of Saliva, p. 512— The Action of Alkaloids, p. 512— Formation of Heat, p. 516 
— Electrical Changes, p. 517 — Section of Glandular Nerves ; the Paralytic 
Secretion, p. 519 — Secretion due to Reflex Action of Peripheral Ganglia, p. 523 
— Direct Irritability of Gland-Cells, p. 524 — Extirpation of the Glands ; injec- 
tion into the Blood of Saliva and of Gland Extracts, p. 524 — General Con- 
siderations ; theories of the Mode of Action of Secretory Nerves, p. 525. 
Some Anatomical Characters of the Salivary Glands. 
In the dog and cat, the sublingual gland enlarges at its end, and 
loses its flattened form ; the enlarged end is closely attached to the sub- 
maxillary gland, and is enclosed in the firm capsule of this gland, so that 
at first sight it appears to form part of it. 
The ducts from the lobules of the submaxillary gland unite, either 
in the connective tissue which stretches from the hilus of the gland, or 
in the hilus itself. The gland duct — the duct of Wharton— runs from 
the hilus to its opening underneath the tongue, without receiving, except 
in rare cases, any further accession. 
The sublingual gland in about its anterior two-thirds consists of 
flattened lobules, the ducts of which enter the main duct on its course 
1 Physiological investigations on the salivary glands have, for the most part, been 
carried out on the larger glands, namely, the submaxillary, the parotid, and the sublingual. 
But such conclusions as we may be able to form with regard to these, we may apply with 
little change to the numerous smaller glands which pour their secretion into the mouth 
and pharynx, and, indeed, to the lachrymal glands and glands of the nasal mucous mem- 
brane also. Both in histological and physiological characters the lachrymal gland 
resembles an albuminous salivary gland. It receives cranial secretory fibres by way of the 
lachrymal branch of the fifth nerve; the origin of these fibres from the medulla has not 
been investigated. It receives sympathetic fibres by way of the cervical sympathetic and 
the blood vessels of the gland. Secretion can be produced reflexly by stimulating most, 
if not all, sensory nerves. 
The animals on which investigations have been made are chiefly the dog, cat, and rabbit, 
the horse, ox, and sheep. 
