MICROSCOPIC ANATOMY OF THE PULP. 



23T 



portion" of the bulk of the tooth. They vary very much 

 in size and shape, being estimated from the ten-thousandth 

 to the one-eighth part of an inch in diameter. They are 

 disposed throughout the pulp in concentric layers, and 

 have granules interspersed among them. 



The microscope of this gentleman also shows the pulp 

 cells to consist of a membrane, cavity and nucleus. The 

 nucleus generally occupies the lateral portion of the cell- 

 wall, though some- 

 times found in the 

 centre of its cavity. 

 The nuclei of all 

 the cells are compo- 

 sed of animal tissue, 

 and remain as such 

 without any trans- 

 formation ; while the 

 cells themselves un- 

 dergo a "conversion" into ivory, by the deposition in their 

 interior of calcareous salts. The nuclei, arranged in a 

 "linear succession," constitute "the fibres of the ivory," 



FIG. 64, A, the Cellular arrangement in a portion of the body of the pulp. 



FIG. 64, B represents the presence of Vesicles on the superficial layer of the 

 pulp not an unfrequent occurrence according to Mr. Nasmyth. 



FIG. 64, C, another variety in the arrangement of the Cells of the pulp. 



FIG. 65, A represents the baccated or beaded appearance of Dentine, accord- 

 ing to Mr. Nasmyth. 



FIG. 65, B represents a portion of the Pulp, as well as the ivory, and shows 

 the fibres to be continuous with the parietes of the cells. 



