author's absteact of this paper issued 

 by the bibliographic service, august 5 



THE COMPARATIVE HISTOLOGY OF THE ENAMEL 



ORGAN OF THE MAMMALIAN TOOTH, WITH 



SPECIAL REFERENCE TO ITS BLOOD 



SUPPLY 



H. E. JORDAN 



Department of Histology and Embryology, Medical School, University of 



Virginia 



SIX FIGURES (three PLATES) 



INTRODUCTION 



This investigation seeks as its primary object to determine 

 whether the enamel organ of the teeth of mammals is character- 

 ized at any stage of its development by an intrinsic blood supply. 

 It aims further to explain the current confusion regarding this 

 question. Among recent investigators, Williams, Hopewell- 

 Smith, and Noyes claim that the enamel organ in certain higher 

 mammals contains blood capillaries. Skillen, Jordan, and others 

 claim that no blood vessels actually penetrate the enamel pulp 

 ('stellate reticulum'). Skillen is unable to detect intrapulpar 

 capillaries even in sections of injected specimens. Possibly the 

 claim of an intrapulpar blood supply is based in part upon the 

 observation of isolated blood corpuscles within the stellate 

 reticulum. The presence of intrapulpar erythroplastids must be 

 admitted. A complete solution of our problem demands, there- 

 fore, an explanation of the occurrence of occasional extravascular 

 red blood-corpuscles within the enamel organ. 



Not only as regards the question of presence or absence of 

 blood vessels in the enamel pulp is there sharp difference of 

 opinion, but disagreement also prevails concerning the depth 

 to which the alleged intra-amelopulpar capillaries invade the 

 stellate reticulum. Hopewell-Smith and Tims state that in the 

 wallaby the capillaries which invade the enamel organ penetrate 



379 



