604 



OLFACTORY MUCOUS MEMBRANE. [.sect. 235. 



microscopical examination, it is seen to be bounded by a -pretty- 

 distinct dentated or undulating margin. The peculiarities of its 

 structure are dependent on the nature of its epithelium, on the 



Fisr. 247. 





Wnll/Hlifii) ^jjjhlj 'UiilLHuitjHUnDml 



cSdr - ^zii^zy ^ 



From the nasal mucous membrane ut the .sheep; magnified 150 times. 1. Trans- 

 verse section of the mucous membrane, from the proper olfactory region ; a. epi- 

 thelium without cilia; b. olfactory nerves, with a dividing pale nucleated bundle; c. 

 gland of Bowman ; d. aperture of the same. 2. Ciliated epithelium of the Schneiderian 

 membrane. 



occurrence of numerous glands of a peculiar nature, which I will 

 call the ' glands of Boioma?i/ and, lastly, on the arrangement of 

 the nerves. The epithelium is not at all ciliated in the lower 

 animals, but in man cilia do exist in certain places, while in other 

 spots they are wanting {JEcker, M. Schultze); it is also much 

 thicker than the epithelium, of the ciliated region, so that in the 

 sheep, where the latter measures o'03"', the layer in question 

 measures o"05"'; and in the rabbit, they amount to 0*04'" and 

 0*07'" respectively. Notwithstanding this thickness, which is 

 considerable for an epithelium, it is extremely delicate and soft, 

 and can only be preserved, so as to show its separate elements 

 distinctly, in certain particular solutions (v. infra). According to 

 the more recent observations of Eckliard, and the still more valu- 

 able ones of M. Schultze, which have been confirmed in all respects 

 by Ecker and myself, this epithelium has but one single layer of 

 very long cells, between which are inserted other cellular struc- 

 tures, the apparent terminations of the olfactory nerve, or the 

 olfactory cells (M. Schultze). The epithelial cells have exactly the 

 structure of the elongated cells of ciliated epithelium, with this 

 difference, that their filiform, irregularly defined, processes run 

 down quite to the surface of the mucous membrane, and at their 



