THE NASAL FOSSAE, PHARYNX, AND TONSILS. 371 



the occurrence of peculiarly constructed glands Bowman's 

 glands and upon the relations of the nerves. 



The fundamental layer of the mucous membrane is com- 

 posed of a finely fibrillated connective tissue, rich in cells, the 

 arrangement of which is determined by the numerously dis- 

 tributed glands, nerves, and vessels which it contains. As. in 

 the other regions of the nasal cavity, the iriucosa seems to pass, 

 without a well-defined limit, into the periosteum. In many 

 places aggregations of small pigmented nuclei are found, some 

 in the shape of long strips lying near the nerve-branches, some 

 in other situations, in rounded or irregular groups. 



The olfactory epithelium attains a considerable thickness. 

 It consists of a single layer of very elongated cells, which 

 Schultze has proved to be of two kinds, epithelial cells and 

 olfactory cells. 



The olfactory cells are slender, delicate structures, in which 

 may be distinguished a cell-body and two prolongations going 

 in opposite directions the one to the periphery, the other cen- 

 trally. The bodies of the olfactory cells are not all located in 

 the same plane of the epithelial stratum. The majority, how- 

 ever, occupy its deeper portions. The cell-body appears spin- 

 dle-shaped or pyriform. It is finely granulated, and has in its 

 central and widest portion a spherical, light-colored, ill-de- 

 fined nucleus. The peripheral prolongation is generally rod- 

 shaped, but now and then presents slight sinuosities. It is 

 sharply outlined and homogeneous, and its free extremity, in 

 some animals (amphibia and birds), has a tuft of the most deli- 

 cate hairs, which project above the surface of the epithelium. 

 In man this is not the case. The opposite prolongation is ex- 

 tremely delicate and perishable, and, by some methods of 

 preparation, resembles the finest nerve-fibrils, sometimes cov- 

 ered with varicosities, at others entirely smooth. It runs con- 

 tinuously and undivided as far as the base of the epithelial 

 stratum, where it appears to meet the final radiations of tin; 

 olfactory nerve, partly intertwines with these radiations, and 

 then escapes further investigation. 



The indifferent epithelial cells appear in the form of an 

 elongated cylinder with a very fine, granulated cell-body and 

 an ellipsoid nucleus. Near the latter the cell suddenly con- 

 tracts into a slender, veiy pale, centrally directed prolongation, 

 the inferior end of which becomes somewhat wider, and 



