THE SALIVARY GLANDS. 153 



the second grinder, a needle was found lying- longitudinally, and which had penetrated 

 from the side to the inferior portion of the tongue. It was an inch and a quarter in 

 length, and the neighbouring substance was in a state of gangrene. 



Vesicles will sometimes appear along the under side of the tongue, which will 

 increase to a considerable size. The tongue itself will be much enlarged, the animal 

 will be unable to swallow, and a great quantity of ropy saliva will drivel from the 

 mouth. This disease often exists without the nature of it being suspected. If the 

 mouth is opened, one hirge bladder, or a succession of bladders, of a purple hue, will 

 be seen extending along the whole of the under side of the tongue. If they are lanced 

 freely and deeply, from end to end, the swelling will very rapidly abate, and any 

 little fever that remains may be subdued by cooling medicine. The cause of this 

 disease is not clearly known. 



THE SALIVARY GLANDS. 



In order that the food may be properly comminuted preparatory to digestion, it is 

 necessary that it should be previously moistened. The food of the stabled horse, 

 however, is dry, and his meal is generally concluded without any lluid being offered 

 to him. Nature has made a provision for this. She has placed in the neighbournood 

 of the mouth various glands to secrete, and that plentifully, a limpid fluid, somswhat 

 saline to the taste. This fluid is conveyed from the glands into the mouth, by various 

 ducts, in the act of chev/ing, and, being mixed with the food, renders it more easily 

 ground, more easily passed afterwards into the stomach, and better fitted for diges- 

 tion. 



The principal of these is the parotid gland (see cut p. 125). It is placed in the 

 hollow which extends from the root of the ear to the angle of the lower jaw. A por- 

 tion of it, Y, is represented as turned up, to show the situation of the blood-vessels 

 underneath. In almost every case of cold connected with sore throat, an enlargement 

 of the parotid gland is evident to the feeling, and even to the eye. It is composed 

 of numerous small glands connected together, and a minute tube proceeding from 

 each, to carry away the secreted fluid. These tubes unite in one common duct. At 

 the letter w, the parotid duct is seen to pass under the angle of the lower jaw, together 

 with the submaxillary artery, and a branch of the jugular vein, and tiie}"- come out 

 again at w. At r, the duct is seen separated from the other vessels, climbing up the 

 cheek, and piercing it to discharge its contents into the mouth, opposite to the second 

 grinder. The quantity of fluid thus poured into the mouth from each of the parotid 

 glands amounts to a pint and a half in an hour, during the action of mastication ; and, 

 sometimes, when the duct has been accidentally opened, it has spirted out to the dis- 

 tance of several feet. 



The parotid gland sympathises with every inflammatory affection of the upper part 

 of the throat, and therefore it is found swollen, hot, and tender, in almos*: every catarrh 

 or cold. Tlie catarrh is to be treated in the usual way ; while a stimulating applica- 

 tion, almost amounting to a blister, well rubbed over the gland, will best subdue the 

 inflammation of that body. 



In bad strangles, and, sometimes, in violent cold, this gland will be much enlarged 

 and ulcerated, or an obstruction will take place in some part of the duct, and the 

 accumulating fluid will burst the vessel, and a fistulous ulcer will be formed that will 

 be very difficult to heal. A veterinary surgeon alone will be competent to the treat- 

 ment of either case ; and the principle by which he will he guided, will be to heal 

 the abscess in the gland as speedily as he can, and, probably, by the application of 

 the heated iron: or, if the ulcer is in the duct, either to restore the passaije tlirough 

 the duct, or to form a new one, or to cut off the flow of the saliva by the destrr.ction 

 of the gland. 



A second source of the saliva is from the submaxillary glands, or the glands under 

 the jaw. One of them is represented at s, p. 125. The submaxillary glands occupy 

 the space underneath and between tliR sides of the lower jaw, and consist of numer- 

 ous small bodies, each with its proper duct, uniting together, and forming on each 

 side a common duct or vessel that pierces through the muscles at the root of the 

 tongue, and opens in little projections, or heads, upon the frienum, or bridle of the 

 tongue, about an inch and a half from the front teeth. When the horse has catarrh 



u 



