ORGAN OF SMELLING. 397 



scent, on a level with the posterior end of the latter, it detaches 

 another filament, which supplies the mucous membrane, along 

 the inferior margin of this bone. 



An opinion advanced by Mery about the close of the seven- 

 teenth century, has lately been revived by M. Magendie, of 

 Paris, that the olfactory nerves are not those which communi- 

 cate the impressions of odorous bodies. In contradiction, how- 

 ever, to his experiments, it should be stated, that several re- 

 spectable anatomists have seen cases where the privation of the 

 sense of smell during life, was found, upon examination after 

 death, to be attended with the absence of the olfactory nerves. 



Of the Blood Vessels of the Nose. 



The extreme vascularity of the Schneiderian Membrane is 

 derived from several sources. The Internal Maxillary Artery 

 sends through the Spheno-Palatine Foramen a large branch, 

 which is distributed upon the septum and upon the spongy bones. 

 The palatine artery also supplies this membrane with one or 

 more small branches. The Ophthalmic also sends the anterior 

 and the posterior ethmoidal branches to it, from the orbit of the 

 eye. The Infra-orbitar artery likewise contributes to its vascu- 

 larity by one or more branches, sent off in its course through 

 the infra-orbitar canal. 



The veins follow the course and distribution of the arteries. 

 Some of them, however, unite with the trunks called emissa- 

 ries of Santorini, which come from the sinuses of the dura ma- 

 ter through the foramen ovale and rotundum of the sphenoid 

 bone. 



CHAPTER II. 



OF THE EYE, AND ITS DEPENDENCIES. 



THE organ of vision which depends upon the optic nerve for 

 its usefulness, is formed by the Ball of the Eye and many De- 

 VOL. II. 35 



