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GLOSSARY. 



Myosin, /uu? a muscle; muscle- 

 fibrin obtained from living 

 muscle. 



Nares, the nostrils ; anterior nares 

 the nostrils proper ; posterior 

 wares the openings of the nasal 

 cavities into the pharynx. 



Necrosis, ye/cpo's a dead body ; the 

 death of a mass of bone. 



Nitrogenous, containing nitrogen ; 

 organic substances containing 

 nitrogen are so called. 



Notochord, I/OITOS the back, and 

 XopM a string; the embryonic 

 structure round which the 

 bodies of the vertebrae are de- 

 veloped, called also chorda dor- 

 sails. 



Nucha, an un classical word for 

 the neck; ligamentum nucJice, 

 the ligament which in many 

 animals suspends the head from 

 the spines of the vertebrae. 



Nucleus, a kernel; a firm albu- 

 minoid structure in the interior 

 of a living corpuscle, or such a 

 structure in a matrix, though 

 no corpuscle be seen to surround 

 it. 



Nucleolus, diminutive of nucleus; 

 a dense body within the sub- 

 stance of a nucleus. 



Occipital, occiput (ob and caput) 

 the hinder part of the head ; 

 the name of the hindermost 

 bone of the skull. 



Ocellus, diminutive of oculus, a 

 little eye ; applied to a minute 

 eye or a unit of a compound eye 

 in the invertebrata. 



Odontoid, o<5ous a tooth, and t<5os 

 form ; like a tooth ; the name 

 of the process surmounting the 

 body of the second cervical ver- 

 tebra. 



(Esophagus, o'tcru) future of <pepw 

 I bear, and tyayelv to eat ; the 

 bearer of things eaten ; the di- 

 gestive tube from the point at 

 which it becomes a completely 

 separate tube at the termina- 

 tion of the pharynx, down to 

 the entrance of the stomach. 



Olecranon, wXe'i/i; the elbow, and 

 Kpaviov the top of the head ; the 

 summit of the ulna. 



Olivary, like an olive ; olivary 

 eminence of medulla oblongata, 

 and olivary process of the 

 sphenoid bone. 



Omasum (w/uo's raw) a tripe ; the 

 third stomach of a ruminant, 

 called in French feuillet. 



Omphalo-mesenteric, d/uupaXo's the 

 ravel (see Mesentery) ; the name 

 of vessels in the young foetus 

 which return blood from the 

 walls of the umbilical vesicle. 



Operculum, a lid. The qpercula 

 of the tooth sacs cover in those 

 cavities. 



Ora serrata (serra a saw), the ser- 

 rated margin ; the anterior 

 border of the retina, so called 

 from its serrated appearance in 

 the human eye. 



Orbit, orbit a the tract in which 

 anything rolls ; the socket of 

 the eyeball. 



Organ, opyavov an instrument 

 (epyov work). 



Organic world, all structures hav- 

 ing organs ; namely, animals 

 and vegetables. 



Organic matter, such chemical 

 compounds as are derived from 

 the organic world. 



Organic functions, processes of 

 nutrition, independent of con- 

 sciousness ; in contradistinction 

 to animal functions, in which 

 consciousness is involved. 



Organism, a being with organs ; 

 any plant or animal. 



Organized, having organs ; diff- 

 erentiated structure. 



Os magnum, large bone ; the larg- 

 est of the eight carpal bones. 



Os uteri, mouth of the womb. 

 The os externum and internum 

 are distinguished at the lower 

 and upper end of the cervix. 



Osmosis, wdeo) I push ; the dif- 

 fusion of fluids through mem- 

 branes. 



Ossification, os bone, and fado I 

 make ; the formation of bone. 



Osteoblastic, cxrreov bone, and 



