TEETH EMANATING FROM OSSEOUS SYSTEM. 121 



emanating from papillae and mucous membrane, where 

 was the dermoid papilla that constituted the basis of 

 development of this tooth, deeply seated and close to 

 the ear, especially as what might be taken as the 

 crown looked toward the inner surface of the skin ?' 



" Further on Lafosse shows that in certain animals 

 teeth absolutely emanate from the osseous system, as 

 in the coluber scaber and other serpents, in which true 

 osseous eminences, coated by enamel, pierce the esoph- 

 agean tunics, and project into the tube ; they are at- 

 tached to about thirty vertebrae, of which they form 

 the inferior spinous process. These are intended to 

 crush the eggs that the serpents feed upon. 



" Having established the fact that teeth may spring 

 from bone as well as mucous membrane, Lafosse leads 

 us, where we never suspected, to consider the dental 

 tumors above spoken of as congenital, and he looks 

 on them as having sprung from some rudiment of a 

 maxillary bone. In a word, he looks on the abnormal 

 tooth in question without offering any plausible ex- 

 planation as an aberration in development. He does 

 not class such teeth with the teeth formed in the 

 ovary, &c., but rather with those instances where an 

 extra limb or portion of an extremity is to be met with. 

 It is an accidental excess of parts in an otherwise well- 

 formed body. i It cannot,' says Lafosse, ' be looked on 

 as an osseous transformation of certain tissues/ 



"I have spoken of the case at length, for surgically 

 it is of the very greatest interest. As pathological 

 anatomists, it is our duty to study the laws of disease 

 as well as health. It is praiseworthy to dive into the 

 mysteries of the origin of monsters, but it is essential 

 to adhere to facts and not sacrifice them to theoretical 

 explanations. 

 6 



