52 



ELEMENTARY PHYSIOLOGY. 



are covered with a strange coat, as iu disease, our 

 food does not taste natural. 



WHAT 



WHEBE? 



WHY? 



OUTLINE. 

 ORGANS OF THE SPECIAL SENSES. 



T Eye the organ of sight. 



J Ear the organ of hearing. 



] Nose the organ of smell. 



i_ Tongue the organ of taste. 



f Eye under arch of frontal bone. 



J Ear in hollow of temporal bone. 



I Nose at entrance of air and food passages. 



^ Tongue lies on the floor of the mouth. 



f Eye to collect rays of light from objects and pro- 

 duce a picture or image of such objects on the 

 expansion of the nerve of sight. 

 Ear to collect sound waves and convey them to 



the nerve of hearing. 

 Nose to bring odorous matter in contact with the 



?aerve of smell. 



Tongue to bring substances having taste in con- 

 tact with the nerve of taste. 



QUESTIONS. 



Where are the nerves of common sensation distributed ? 



How many nerves of special sensation are there ? 



Can these nerves receive impressions directly ? 



What is the special instrument of the nerve of sight"? 



What is the proper name of the nerve of sight ? 



By what only is it impressible ? 



What is the use of the eye ? 



How is the eye protected by its position ? 



What other means of protection are furnished it ? 



What is the use of the lachrymal or tear gland ? 



Where is this gland situated ? 



After bathing the eye, how is that fluid drained away ? 



What is meant by "shedding tears" ? 



What conditions of mind and body may cause this 



