THE STRUCTURE OF THE TEETH 71 



weakest. The diffusion of the " black," too, at once strikes 

 the practised eye as unnatural. 



Tiuelve to Twenty Years Old. — It is a generally received 

 opinion that after the disappearance of the mark from the 

 outer incisors, at the eighth year, all certainty with regard 

 to the horse's age is over. As to the marks, this is true ; as 

 to other criteria, enlarged research has shown it to be only 

 partially so. The teeth increase in obliquity, and apparently 

 in length. From birth to six years the study of the regular 

 progress of the development of the mouth has almost the 

 character of an exact science, and the age to a year can be 

 pronounced. At the period we have now arrived at, mere 

 generalities supply the place of particular marks ; and 

 further than the fact that the horse is old, growing rapidly 

 old, prematurely old, or, on the contrary, sound and good, his 

 years being taken into account, our chart-knowledge does 

 not exactly guide us. We think, however, that the 

 characteristics of the mouth at twelve and, say, twenty years 

 are sufficiently distinctly marked to enable an approximate 

 j udgment, if not a confident and exact one. Some Continental 

 writers of eminence resort to the upper nippers as showing 

 the " mark " from the ninth to the twelfth 3^ear, but we 

 must confess we have little faith in their guidance in this 

 respect. We may, however, note incidentally that the "bars" 

 of the mouth become less and less prominent as age draws 

 on, first losing rugosity about the ninth or tenth year, and 

 becoming less prominent with advancing age. We may 

 note that stabled horses kept on hard meat do not, as might 

 be expected and has been asserted, show an earlier diminu- 

 tion of less rugosity of the palate than grass or softer-fed 

 animals ; this may be due to the active stimulation of 

 a part well calculated to keep up its bulk and healthy 

 renewal by its numerous blood-vessels and its protected 

 position. 



The indications of age connected with decay are not 

 equivocal, but show themselves in the sunken eyepits and 

 dimmed eyeballs. In such an one the lips will also be thin 

 and pendulous, the under or hinder lip extremely so ; 

 the anus, not wedged up by interstitial matter heretofore, 

 and not sufficiently retracted by its weakened muscles, now 

 projects considerably. The grey horse becomes white, 

 and the darker colours become intermixed with grey, 

 particularly about the head ; the bony processes in every 



