224: 



ANIMAL PHYSIOLOGY. 



B 



merits of the soft and nucleated variety, and ramify beneath 

 the mucous membrane of the upper and middle turbinated 

 bones and the ethmoidal part of 

 the nasal septum; and in this, 

 which is termed the olfactory 

 region, the mucous membrane of 

 the nose, called also the Schnei- 

 derian or pituitary membrane, is 

 softer and smoother, and has the 

 mucous glands smaller than they 

 are in the lower part of the nasal 

 fossse. The olfactory mucous mem- 

 brane is likewise distinguished by 

 being clothed with a non-ciliated 

 columnar epithelium. But be- 

 tween the ordinary columnar cells 

 are scattered slender nucleated 

 bodies, each of which is in con- 

 tinuity with a filament of olfac- 

 tory nerve, and in birds and 

 amphibia is furnished with a 

 single hair or a bundle of fine 

 cilia. These are called olfactory 

 Fig. 110. OLFACTORY CELLS, cells; and we are led to believe 

 with the epithelial cells be- that tlie WO nderfully and impon- 

 tween which they lie; both -, , , . -, J 



with deep connections. A, clerably minute odorous particles 

 Human. B, From frog, drawn into the nasal fosssa in 

 After Schultze and Frey. inspiration affect their extremi- 

 ties, and, through them, the olfactory nerves. 



185. Taste is a sense which is closely allied to both 

 common sensation and smell, and as it is less definite in its 

 nature than the other special senses, so also it is dependent 

 on a less definitely distinguished nervous supply; for while 

 smell, sight, and hearing, have each a special nerve devoted 

 to them, the organ of taste has its sensory supply from two 

 mixed nerves, the glosso-pharyngeal and the gustatory or 

 lingual branch of the fifth. 



The organ of taste is the upper surface of the tongue. 

 This is covered with papillce, which differ from those on the 

 general surface of the skin, not only in being larger, but also 



