DIGESTION OF FOOD. 321 
3. If a glass tube be placed in the duct of the gland and any 
substance that naturally causes a flow of saliva be placed on 
the tongue, saliva may be seen to rise rapidly in the tube. 4. 
The same may be observed if the lingual nerve, the glossopha- 
ryngeal, and many other neryes be stimulated; also if food be 
introduced into the stomach through a fistula. 5. If the pe- 
ripheral end of the chorda tympani be stimulated, two results 
follow: (a) There is an abundant flow of saliva, and (b) the 
arterioles of the gland become dilated; the blood may pass 
through with such rapidity that the venous blood may be 
“bright red in color and there may be a venous pulse. 7. Stimu- 
lation of the medulla oblongata gives rise to a flow of saliva, 
which is not possible when the nerves of the gland, especially 
the chorda tympani, are divided; nor can a flow be then excited 
by any sort of nervous stimulation, excepting that of the ter- 
minal branches of the nerves of the gland itself. 8. If the sym- 
pathetic nerves of the gland be divided, there is no immediate 
flow of saliva, though there may be some dilatation of its ves- 
sels. 9, Stimulation of the terminal ends of the sympathetic 
and chorda nerves causes a flow of saliva, differing as to total 
quantity and the amount of contained solids; but the nerve 
that produces the more abundant watery secretion, or the re- 
verse, varies with the animal, e. g.,in the cat chorda saliva is 
more viscid, in the dog less so; though in all animals as yet 
examined it seems that the secretion as a result of stimulation 
of the chorda tympani nerve is the more abundant; and in the 
case of stimulation of the chorda the vessels of the gland are 
dilated, while in the case of the sympathetic they are con- 
stricted. 10. If atropin be injected into the blood, it is impos- 
sible to induce salivary secretion by any form of stimulation, 
though excitation of the chorda nerve still causes arterial dila- 
tation. 
Conclusions.—1. There is a center in the medulla presiding 
over salivary secretion. 2. The influence of this center is 
rendered effective through the chorda tympani nerve at all 
events, if not also by the sympathetic. 3. The chorda tym- 
pani nerve contains both secretory and vaso-dilator fibers; the 
sympathetic secretory and vaso-constrictor fibers. 4. Arterial 
change is not essential to secretion, though doubtless it usually 
accompanies it. Secretion may be induced in the glands of 
an animal after decapitation by stimulation of its chorda 
tympani nerve, analogous to the secretion of sweat in the foot 
of a recently dead animal, under stimulation of the sciatic 
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