DENTITION AND DENTAL DISEASES 245 



for years. The tooth opposite, in the lower jaw, had to be kept 

 down by rasping every three or four months. 



359. Wolf Teeth are found in the upper jaw immediately in front 

 of the first premolars, and are generally thrown off when the horse 

 casts the crowns of the two first premolars on rising three years old J 

 but I have seen them in aged animals, and, in my opinion, they do 

 no harm. I have never known them affect the sight of the horse, as 

 is stated by some. 



360. Parrot-mouthed animals are known by the upper jaw 

 being much longer in front, overlapping the lower, when the teeth 

 in the latter become elongated from not meeting the wear of the 

 upper teeth, and in time injure the bars or gums of the upper jaw. 

 These cases have to be closely watched, and the teeth dressed 

 when necessary. Sheep seem to be most subject to this peculiar 

 formation. 



CATTLE. 



361. The cow, which I shall take as my illustrative type, has 

 eight incisors, or, as is now taught, six incisors and two canine 

 teeth, which are shovel-shaped, and with well-defined necks; but they 

 are found in the lower jaw only, and are always loose in their sockets, 

 the upper jaw being provided with a cartilaginous pad. 



362. The shedding of teeth in cattle is very irregular, varying 

 fully six months in their development, according to the breed and 

 mode of feeding, but the following may be taken as a fair average : 

 At birth (1) a calf may have from two to six incisors and two canine 

 in the lower jaw, and twelve premolars (three on each side, above 

 and below), all of which are temporary or milk teeth. About six 

 months after birth (2) the fourth tooth, or the first permanent molar, 

 makes its appearance ; at from fifteen to sixteen months (3) the fifth 

 tooth, or second permanent molar, is seen ; and at two years (4) the 

 sixth tooth, or third permanent molar, is through. About this 

 period (5) the temporary, first and second inferior, and first superior 

 premolars are thrown off, and six permanent teeth take their place. 

 The first inferior premolar is very like a wolf tooth in the horse. The 

 second inferior premolar is much larger (Plate XXX II., C, 2), and 



