254 



A MANUAL OF DENTAL ANATOMY. 



in use. Thus, in Fig/ 105, the poison [fang of the snake's 

 right side is seen occupying a position on the extreme out- 

 side of the maxillary bone, while its left poison fang is fixed 

 on the inside of the maxillary bone. 



The upper boundary of Fig. 108 is formed by the flap 

 of mucous membrane which covers in the poison fang when 

 at rest. Nos. 1 and 2 lie in the pouch formed by it, the 



FIG. 108 



iD 



section happening to be taken from a specimen in which the 

 tooth was about to be changed. In most specimens one 

 tooth only, the tooth actually in use, is seen in this position. 

 A flap hanging free across this space serves apparently to 



( l ) Transverse section of the reserve poison fangs of a Viper. 1. Tooth 

 at present in use, in its recumbent position ; were it erect, it would be 

 withdraAvn from view, or else seen in longitudinal section. 2. Tooth which 

 will next succeed to No. 1. 3, 4, 5, &c. Tooth-sacs numbered in the order 

 in which they will succeed. 



