INFERIOR EXTREMITY OF THE HEAD. 73 



analogy of their form and position, moustaches. This peculiarity is 

 also more rarely observed on the superior lip. 



Diseases and Blemishes. Diverse diseases, which may ordinarily pre- 

 vent the sale of the animal, are observed in the region of the lips. Besides 

 paralysis, of which we have spoken, farcy ulcers are sometimes observed here 

 over the course of the lymphatics. Ulcers of variola also affect this region, attack- 

 ing young animals principally. These latter ulcers may be situated upon .the ex- 

 ternal surface of the lips, along their free border, as well as in the interior of the 

 buccal cavity, and around the alae of the nostrils. Their gravity is of little con- 

 sequence, and with care and practice we are enabled to distinguish them easily 

 from the preceding, which are characteristic and serious in the extreme. Besides 

 these alterations, the lips are the seat of swellings which disfigure the parts be- 

 cause they extend into the surrounding tissues. Such are O3dematous effusion 

 due to anasarca, the prolonged ingestion of certain plants, as buckwheat, for 

 example, or the accidental application of vesicants, as when the animal rubs 

 a surface which has been blistered for a therapeutic purpose. 



The most common blemishes of the lips are excoriations and cicatrices, 

 resulting from the application of the twitch. These are always an indication of 

 a vicious habit of the animal, difficulty in shoeing, or of his having been subjected 

 to a surgical operation requiring frequent dressings. It is not rare to meet with 

 cuts or lacerations along their free border. These wounds suggest falls, and it is 

 important to examine with care the condition of the extremity of the nose, the 

 incisor teeth, the gums, and the limbs, to inform ourselves as to the cause which 

 has produced them. 



In old horses it is quite common to see thickenings or lacerations of the one 

 or the other commissure, occasioned by repeated and violent traction on the bit or 

 by a bit which is too narrow and improperly adjusted. These render the com- 

 plete closure of the mouth impossible, and may prove to become obstacles to the 

 prehension of liquids. The pain which they cause may, for a certain time, inca- 

 pacitate the animal for service. 



Let us say, in conclusion, that we often see in horses affected with immo- 

 bility particles of hay or straw adhering to the commissures of the lips and 

 remaining there without provoking the least movement of the jaws. It is then 

 said that he smokes his pipe. 



2. The Teeth and the Gums. 



The teeth are organs of osseous appearance, implanted in the 

 alveoli of the maxillary and incisive bones. They assist in the pre- 

 hension and mastication of the aliment, and are distinguished from 

 their use as incisors, canines, and molars. 



The relation of the teeth to the determination of age is so important 

 to recognize that we will devote to it a special chapter. (See Age.) 

 We will content ourselves for the present by saying that their minute 

 examination should be made at the same time as that of the mouth, 

 and include their integrity, soundness, length, direction, and the regu- 

 larity of their surface. 



The mucous membrane which surrounds the teeth and aids to fix 



