SOME NOTABLE ORAL EQUIPMENTS IN THE 

 VERTEBRATA. 



BY MR. FREDERICK ROSE, L.D.S., R.C.S. r ENG. 

 SECTION I. 



As the subject I have undertaken is rather an extensive 

 one, and as many technicalities must necessarily require to 

 be explained so as to make the subsequent subject-matter 

 intelligible to those who have not made a speciality of this 

 branch of Zoology, I have decided to divide it into three 

 sections, which I hope I may have the privilege of deliver- 

 ing on three separate evenings. Section I., which I propose 

 taking for this evening will be somewhat introductory ; 

 but I hope as well to find time to complete all the re- 

 marks I propose to make on the teeth and jaws of the 

 " Cold Blooded Vertebrates." Section II. will include " Warm 

 Blooded Vertebrates" ; and Section III. will be devoted to 

 " Histological Characteristics." 



One would like to make a study of this description 

 either purely synthetic or purely analytical ; and perhaps 

 this would be the more strictly scientific method ; but I 

 think I can make my remarks more comprehensible, if I 

 somewhat depart from this orthodox procedure. 



As you are all more or less familiar with a human tooth, 

 and its mode of implantation in the jaw, it will facilitate the 

 comprehension of other forms of oral equipments to take this 

 as a starting point, and use it as a means of comparison of the 

 lower organisms. 



I have here a human tooth sawn in two longitudinally, 

 and to help towards a recognition of its parts, I have drawn 

 it diagrammatically ; and I shall assume throughout that no 

 one present understands anything about my subject. 



Proceeding from within outwards we perceive a hollow 

 box, closed at the top or crown, and open by a fine tube at 

 the bottom or root. This hollow box has at one time enclosed 



