THE ORGAN OF SMELL. 



499 



of the epithelial layer. Toward the nasal cavity, the cells terminate 

 in blunt cones, upon each of which are several stiff hairs, the olfac- 

 tory hairs. The basilar ends form true centripetal nerve-processes, 

 neuraxes, which end in the peculiar telodendria constituting the glo- 

 meruli of the olfactory bulb. (See p. 422.) 



The nuclei of the sustentacular cells are more oval and are situ- 

 ated at nearly the same level. These cells present the appearances 

 of long columnar cells, which toward the basement membrane ter- 

 minate in one or several processes. Between the basilar ends of 

 these cells we find a layer of elements the broad nucleated bodies of 

 which rest on the basement membrane, while their upper extremities 

 terminate in short superficial processes. 



The mucosa contains a large number of leucocytes as well as 







Fig. 377. Portion of transverse section of the olfactory region of man ; X 1 S ' f * 

 zone of olfactory hairs ; ep, epithelium ; 2, zone of oval nuclei ; j, zone of round nuclei ; 

 gl, olfactory or Bowman's glands; n, branch of olfactory nerve; fp, mucosa or tunica 

 propria with blood-vessels (Sobotta, "Atlas and Epitome of Histology"). 



numerous branched tubular glands, the so-called olfactory glands or 

 the glands of Bowman. In man these are albuminous (serous) 

 glands, and their cells sometimes contain pigment. 



Jacobson's organ consists of blindly ending tubes, situated at 

 the lower portion and at the outer side of the nasal septum. It is 

 lined by an olfactory mucous membrane and receives a branch of the 

 nasal nerve. This organ is rudimentary in man. 



The capillaries spread out immediately beneath the basement 

 membrane of the epithelium. In the submucous connective 

 tissue, we find a relatively well developed vascular plexus, rich in 

 venous vessels ; this plexus is especially marked at the posterior 

 portion of the inferior turbinate bone, forming here a tissue which 

 resembles erectile tissue. 



