IV 



THE SENSE OF SMELL 



161 



relates that the Indians of iVru are capable of perceiving and 

 following up the scent of game like hunting - dogs. This is 

 probably due to the fact that tliry preferably use and educate 

 their olfactory sense. Exercise, in fact, perfects the sense of 

 smell hi a remarkable extent; pharmacists are able to recognise 

 drugs and their various properties by smell alone ; experienced 



is is 



Flu. ti2. Frontal section of nasal fossae, seen from behind; the section passes through the back 

 molars. (Testut.) 1, nasal septum: '-', upper; 3, miilille ; 4, lower turbinals ; 5, posterior 



I'thmoid ei-lls opening into 5' (to the right), superior ni'-atus; '., maxillary aiitrum opening 

 into ', middle nieatus; the point of the arrow is in (lie hiatus srim-lunaris ; 7. Imlla 

 ethmoidalis ; s, frontal sinus; '.), eiista galli ; '.>', falx cerebri ; 10, cerebral hemispheres; 

 11, right orbit surrounded by orbital fat. with i-ye-muscles ; 12, great ala of s]ihcnoid ; 13, 

 sphi'iio-maxillary cleft ; 14, adipose tissue of x\.noiiiatic fossa; !;">, biiccinalor muscle; Iti, last 

 molar; 17, vault of palate ; 18, zygoma ; ]'., left orbit. 



physicians diagnose many eruptive diseases at once by their odour; 

 by it wine and oil merchants know the good and bad qualities of 

 their stock-in-trade. Wardrop tells of a man born blind and 

 deaf who distinguished his acquaintances by their smell. 



I. The specific olfactory sensory region consists of a limited 

 portion of the mucous membrane of the nasal fossae. Seen in 

 transverse section (Fig. 62) the nasal fossae appear as an irregular 



VOL. IV M 



