THE TEETH 429 



no true variation, merely some abnormalities due to wear and disease. 

 Bateson describes a tiger's skull with two canines on the right side, 

 both of large size and in the same socket. The anterior was the 

 smaller. Neither was a milk tooth. 



First Upper Premolar ff? -). Size. Out of one hundred 



maxillaries examined, in forty-three this tooth had a single fang, in 

 nine it had two distinct fangs, and in twenty-nine the alveoli were 

 confluent and hence the two fangs were more or less united. In 

 one specimen there were three alveoli, one in front and two confluent 

 behind, but, as the tooth was missing, it is impossible to give any 

 description. Bateson records three cases (presumably out of thirty- 

 eight skulls) of this tooth with double fangs ; in one specimen the 

 variation was on both sides, and in another on the right side only. 



Number. I have found in one hundred maxillaries nineteen ex- 

 amples of absence of the first upper premolar. Hensel notes thirteen 

 examples in two hundred and fifty-two skulls, six times on both sides, 

 once on one side only. Batesou records five cases in thirty-eight 

 skulls, twice on both sides and once on the right side. It must be 

 remembered that the absence of a tooth does not necessarily imply 

 that it was never present ; in my own observations I have taken care 

 to include only such examples of the variation as occurred in younger 

 and mature skulls wherein the teeth were well developed and the 

 alveolar borders free from caries. 



I have only one skull which shows clearly a supernumerary first 

 upper premolar. Bateson describes one case (out of thirty-eight 

 skulls) in which " internal to and rather behind the left pin 1 is an 

 almost identical copy of it, though rather smaller. Not a milk tooth." 

 Hensel notes eleven cases of double first premolars in two hundred and 

 fifty-two skulls, four times on both sides, twice on the right side, 

 and once on the left side. 



Position. In several specimens in my collection this tooth is 

 placed close to the second premolar. In one maxillary the alveolar 

 border is so short that the first premolar is no more distant from the 

 canine and the second premolar than the second premolar is from the 

 third. 



The Second Upper Premolar f^ ). Size. This tooth 

 varies more than any other in the entire series. In some specimens 



