COMPARATIVE ANATOMY OF THE TEETH. 



291 



B 



gans grow with age, and are found of a size proportionate 

 to the dimensions of the animal. 



Serpents have teeth FlG> 80> B 



both upon the palate 

 and jaws. The ven- 

 omous teeth are at- 

 tached to the upper 

 maxillary bone, and 

 are curved backward 

 in a semi-circular 

 form. The roots are 

 situated in the ante- 

 rior part of the jaw, 

 and 'are not mova- 

 ble, according to Mr. 

 Blandin,butare fixed 

 firmly to the bone; 

 the jaw itself, which 

 is movable, causing 

 the apparent motion. 

 These poisonous teeth 

 are much longer than 

 any other and have 

 a canal running the 

 whole length of the 

 teeth, which contains 

 the excretory duct of 

 the gland furnishing 

 the poison. This ca- 

 nal terminates on the 

 free extremity of the 

 tooth by an opening, 

 through which the animal ejects the poison. The sac sur- 

 rounding the base of the fang has within it several rudi- 



Fio. 80, A, B, C represent the poison Fangs of Serpents. B Longitudinal 

 section of the fang, v poison duct; accented v its outlet. 



FIG. 80, D represents also a section of the poison fang magnified f p showing 

 pulp canal, calcigerous tubes, and dentine enclosing the poison canal. 





