GLOSSARY. 259 



look at). An optical instrument which assists in the examination 



of minute objects. 

 MO'LAR (L. mo'la, a mill). The name applied to the three back teeth 



of each side of the jaw ; the grinders, or mill-like teeth. 

 MO'TOR (L. mo'veo, mo' turn, to move). Causing motion ; the name 



of those nerves which conduct to the muscles the stimulus which 



causes them to contract. 



Mu'cous MEM'BRANE. The thin layer of tissue which covers those in- 

 ternal cavities or passages which communicate with the external air. 

 Mo'cus. The glairy fluid which is secreted by mucous membranes, 



and which serves to keep them in a moist condition. 

 MY-O'PI-A (Gr. m'ao, muo, to contract, and GOI{>, ops, the eye). A de- 

 fect of vision dependent upon an eyeball that is too long, rendering 



distant objects indistinct ; near-sight. 

 NA'SAL (L. na'sus, the nose). Pertaining to the nose ; the n(tsa> 



cavities contain the distribution of the special nerve of smeil. 

 NERVE (Gr. vevpor, neuron, a cord or string). A glistening, white 



cord of cylindrical shape, connecting the brain or spinal cord with 



some other organ of the body. 

 NERVE CELL. A minute, round and ashen-gray eel 1 umnd in the 



brain and other nervous centres. 

 NERVE FI'BRE. An exceedingly slender thread of nervous tissue 



found in the various nervous organs, but especially in the nerves ; 



it is of a white color. 

 NU-TRI'TION (L. nu'trio, to nourish). The processes by which the 



nourishment of the body is accomplished. 

 (E-SOPH'A-GUS (Gr.). Literally, that which carries food. The tube 



leading from the throat to the stomach ; the gullet. 

 O-LE-AG'I-NOUS (L. o'leum, oil). Of the nature of oil : applied to aii 



important group of food-principles the fats. 



OL-FAC'TO-RY (L. olfa'cio, to smell). Pertaining to the sense of smell. 

 OPH-THAL'MO-SCOPE (Gr. o<p3o:/l//o?, ophthalmos, the eye, and GKO~ 



item, skopeo, to look at). An instrument devised for examining the 



interior of the globe of the eye. 



OP'TIC (Gr. oTtTGOj opto, to see). Pertaining to the sense of sight. 

 OR'BIT (L. or'bis, the socket). The bony socket or cavity in which 



the eyeball is situated. 

 OS'MOSE (Gr. aodjuoS, osmos, a thrusting or impulsion). The process 



by which liquids are impelled through a moist membrane. 

 OS'SE-OUS (L. os, a bone). Consisting of, or resembling bone. 

 PAL' ATE (L. pala'tum, the palate). The roof of the mouth, consisting 



of the hard and soft palate. 



