IRREGULARITIES BY UNITING OF TWO INCISORS. 



127 



mined by examination of the jaw after death. Incisor, tush, 

 or molar teeth may be absent. 



The tush tooth is tlie one which is most frequently absent, 

 — a condition, however, which is practically normal in mares. 



IRREGULARITIES OF FORM. 



In certain subjects the incisors of the lower jaw present, at 

 the age of six years, a decided triangular form, such as is usually 

 seen at fourteen to fifteen years of age. 



Fig. 1:«. 

 Absence of corner incisors. 



Fig. 134. 

 Double cnp of left intermediate tooth. 



This triangularity is readily distinguished from that of the 

 older age by the presence of the cup. 



IRREGULARITIES BY UNITING OF TWO INCISORS. 



This sort of irregularity has no special importance as to the 

 determination of age, but is interesting as a curiosity. Figure 

 13 J: shows the upper jaw of a horse with a double left-hand 

 intermediate tooth, in which the two cups are perfectly 

 distinct. • 



