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A MANUAL OF DENTAL ANATOMY. 



the canal is quite closed in, has a very marked line along 

 its front, and in section it looks much as would the dentine 

 in Fig. 106, if the two cornuahad their rounded extremities 

 brought together into actual contact, without, however, 

 their rounded outline being altered. 



But in the poison fang of a viperine snake the lips of the 

 groove are flattened and fitted to one another, so that not a 

 vestige of the join can be seen upon the smooth exterior of 

 the tooth. In the accompanying figure the pulp cavity is 

 seen to be a thin flattened chamber partly surrounding the 

 tube formed for the conveyance of the poison. 



The poison-fang is exceedingly sharp, its point being con- 

 tinued some little distance beyond the place where the 

 poison canal opens on the front of the tooth ; this disposi- 

 tion of parts has been copied in the points of syringes for 

 making subcutaneous injections. 



(*) Transverse section of the poison fang of a Rattlesnake, a. Pulp- 

 cavity, d. Dentine. 



