DENTITION IN THE OX. 57 



off," or " coming four." This often retards their eruption, 

 which is always complete at four years, when the sixth 

 molar tooth on either side of each jaw is also advanced 

 through the gum. By this time the three temporary grin- 

 ders or molar teeth, which are noticed shortly after birth, 

 have given way to permanent teeth. The lower tushes are 

 felt through the membrane, between the corner incisor and 

 first molar, as early as three years of age; but they only 

 appear above it between four and five. It is at this age 

 that the horse's mouth becomes fully furnished, and by five 

 the whole of the incisors are in full wear, and indicate the 

 extent to which they have been worn proportionate to the 

 period since their eruption. The central incisors then appear, 

 as shown in b, Fig. 19, whereas the corner ones having just 

 protruded, are shelly, as shown in a. 



At six years the central incisors lose their mark ; at seven 

 this occurs with the middle ones ; and at eight all the in- 

 fundibula are worn out, and the plate of the tooth is clean, 

 and only very slightly marked in the corner teeth. Beyond 

 this period the horse is stated to be aged. The incisors 

 protrude straighter from the receding jaw the teeth become 

 narrower and their wearing surface acquires a triangular 

 form, as seen at c, d, and/, Fig. 19. This distinguishes 

 the old animal. 



DENTITION IN THE Ox, The incisor teeth of the lower 

 jaw of the ox are simple,, and eight in number. From the 

 periods of eruption of both temporary and permanent teeth 

 being regular, the age of the animal is readily recognised. 

 Beyond the eruptive changes we observe the sharp teeth 

 becoming more and more blunt and narrow, until reduced to 

 very small stumps, which are seen in old cattle. The sub- 

 joined table indicates the succession in the changes observed 

 in the ox : 



