CAVITY OF THE MOUTH. 195 



blood vessels. Over this the outer membrane (called the 

 buccal), covering the other parts within the mouth, is re- 

 flected ; only to protect the gums, during the mastication of 

 hard substances, it is here furnished with a cuticle of con- 

 siderable thickness. The membrane just alluded to (the 

 buccal) is reflected all over the interior of the mouth ; being 

 continuous with that which enters the lungs and abdomen, 

 and is part of the great mucous track. When we say the 

 gums are deficient in sensibility, those parts are alluded to 

 only as in a healthy state. When diseased they become 

 highly sensitive. 



The palate of the horse is spoken of as hard and soft. 

 The hard palate {Plate VII. i) is that part touched and 

 felt by the tongue. The soft palate {Plate W.f; Plate 

 VII. I) falls down behind the tongue, and divides the 

 mouth from the fauces. 



The hard palate is highly vascular, and is principally 

 formed of condensed cellular tissue. It is covered by a 

 portion of that thick insensitive buccal membrane which 

 envelops the gums. It is marked across from side to 

 side by curved projecting lines, whicli are called the bars 

 {Plate VII. i). The convexity of these curves point for- 

 ward ; but the projecting edge of rather more than the 

 anterior half looks backward, and that of the remainder 

 faces forward. The use of these formations {the bars) is to 

 keep the food within the mouth ; as but for their existence, 

 from the pendent position of the horse's head, it would be 

 very likely to fall out, an accident which now rarely hap- 

 pens. 



The tongue {Plate VI. e) is that large fleshy body, for 

 the residence of which the cavity of the mouth appears to 

 be formed. It is covered by (the buccal) mucous mem- 

 brane, the same as shields the gums and envelops the 

 palate. The very top of the tongue has papillic, or emi- 

 nences upon it ; which indeed are upon the whole of the 

 superior surface of the organ, only of smaller size, ante- 

 riorly and laterally. It is free at its foremost end ; but 

 only for a small distance, being then bound down to the 

 bottom of the mouth by a fold of the lining membrane, 

 which is termed the frenum. It is principally composed of 

 muscular fibre and glandular substance, with which, how- 



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