54 



incisors not being perceptible at the same time in the 

 mouth of a thirty-years old, entirely springs from the 

 acuteness of the angle which they form at that 

 period. The bars, as years accumulate, also change 

 their positions, being drawn upwards. From the space 

 between the corner incisors and the first molars, the 

 tongue on either side protrudes, as if the narrowed 

 cavity left not sufficient room for the organ to repose 

 in. The extent to which the tongue will project may 

 be conjectured, by regarding the representation of it 

 given in the coloured plate of the thirty-year old 

 mouth. At that age, the protrusion is too strongly 

 marked to escape the observation of any one whose 

 attention has once been directed to the circumstance. 

 Accompanying the inability to retain the tongue 

 within the jaws, is a constant flow of saliva, which 

 continually falls from the mouth of the old horse 

 when the lips be held apart. The latter fact, the 

 author, when he made the drawings for the present 

 work, had ample experience of, as in some instances 

 it occasioned serious delay. 



30. The incisor teeth, hi old age, have their cha- 

 racteristic signs. Mostly they appear unnaturally 



