142 



TEETH. 



hibited at the period named. The reader will remark that the corner 

 incisors, which are depicted as through the gums, do not yet meet, though 

 these organs point toward each other ; neither has the membrane of the 

 mouth at this time entirely lost the deepened hue of infancy. 



From this date, however, the gums gradually become pale, till, by the 

 completion of the first year, the membrane has nearly assumed that com- 

 plexion which will endure throughout the earlier period of existence. 

 All the incisors are, by the first birthday, well up. The masticatory 

 agent, although consolidated, has not, when the quadruped is one year 

 old, entirely lost the roundness and bluntness of its inferior margin, for 

 which the jaw at birth was peculiarly remarkable. 



This fullness of the bone is caused by all the grinding teeth which are 

 in the mouth when the foal first sees the light being of a temporary char- 

 acter; the enlargement is consequent upon the jaw, therefore, having to 

 contain and to mature the long permanent grinders which, within the 

 substance of the bone, are growing beneath the temporary molars. To 

 contain and to allow the large uncut teeth to become developed, before 

 appearing above the gums, causes the small jaw of a diminutive foal to 

 be disproportionately thick, especially when this part is compared with 

 the same structure in an aged horse; but the mind is reconciled to its 

 apparent clumsiness when apprised of the uses to which the organ is 

 subservient. 



THE JAW OP A ONE-TEAR OLD. 



At one year old, the first permanent tooth appears in the head. This 

 is the fourth molar, or that which is represented as the most backward 

 grinder in the appended engraving. The reader will not fail to remark 

 the greater length which the jaw-bone presents at one year old. The 

 additional extent also in the opposite direction cannot otherwise than be 

 observed. This increase of size was necessitated to cover the increasing 



