lit 



On the Histology of the Hard Dental Tissues. 

 By T. Charters White, M.K.C.S., &c. 



Bead Nov. 26, 1875. 



About four years ago I had the honour of reading a short paper 

 here, in which I directed your attention to the histological charac- 

 ters of that soft dental structure, generally known as the " nerve" 

 of the tooth. I pointed out to you the compound nature of it, 

 and described it as a mass of areolar connective tissue, plentifully 

 supplied with nucleated cells, supporting the minute ramifications 

 of the dental vessels and nerves, and having a remarkable layer of 

 peculiar cells disposed on its external surface, in close connection 

 with the walls of the pulp-cavity. At that time I briefly 

 alluded to the office of these cells as dentine-forming organs, and 

 I desire this evening to show more particularly the part these'cells 

 play in the formation of the largest and most important division of 

 the hard dentinal structures. 



In drawing your attention to these structures, I may as well 

 acknowledge at once the source from whence I derive my informa- 

 tion, for I need not remind you of the difficulties which beset 

 oiiginal investigations in any branch of developmental physiology, 

 difficulties that can only be overcome by such workers as our own 

 Dr. Sharpey and Mr. Tomes, in this country, and by Kolliker and 

 Strieker amongst our foreign savans. I shall, therefore, endeavour 

 fairly to represent their views in this short paper, contenting myself, 

 as far as I am able, by giving you a clear and orderly summary of 

 all that has been done by them in this department of histological 

 work. 



In commencing this undertaking, we must bear in mind the 

 nature and office of the teeth — they are essentially dermal struc- 

 tures — by which I mean that their development partakes largely of 

 that of the skin. They are cuticular appendanges, and, although 

 in administering to the wants of man, they are most suitably placed 



