ANATOMY. 



Those which transmit blood vessels 

 are : 1, canales caroctici : 2, f. spinosa : 

 '1, f. lacera in basi cranii : 4, f. magnum. 



JSones of the face. The ossa nusi con- 

 stitute the arch of the nose. The ossa 

 lacrymaliaorunguisare placed at the fore- 

 part of the inner edge of the orbits, and 

 contain an excavation which holds the 

 lacrymal bag 1 . 



The ossa malarum form the prominen- 

 ces of the cheeks. 



The ossa maxillavia superiora form the 

 largest portion of the upper jaw, and most 

 of the bony palate, or roof of the mouth ; 

 they contain also the upper teeth. 



The ossa palati form the back part of 

 the bony palate. 



The ossa turbinata inferiora are situat- 

 ed in the cavity of the nose. 



The former completes, with the nasal 

 portion of the ethmoid, the septum that 

 divides the two nostrils. 



The maxilla inferior is articulated to 

 the basis cranii, and holds the lower teeth. 



The bones of the cranium and face 

 compose the two orbits, or pyramidal bo- 

 ny cavities, holding the organs of vision ; 

 to each of these, seven bones contribute. 

 They also form the cavity of the nose, 

 which is very extensive, and includes 

 portions of nearly all the bones of the 

 face, and some of the skull. It has va- 

 rious cells, formed in the bones of the 

 skull and face, opening into it. 



The teeth. These organs are composed 

 internally of a very hard bony substance ; 

 and are covered externally by a still hard- 

 er matter, called the cortex or enamel. 

 Each tooth has a body or crown, which 

 is the part seen in the mouth ; a neck, 

 round which the gum adheres ; and one 

 or more fangs or roots, which are sunk in 

 a process of the jaw, called the alveolar. 

 These bodies are not formed in a nidus 

 of cartilage, like bones, but on a soft 

 vascular body called a pulp, which may 

 be compared to the core, on which a horn 

 is formed. This is surrounded by a deli- 

 cute membrane, called the capsule of the 

 tooth. When the teeth are being formed, 

 these pulps and capsules, with the rudi- 

 ments of the teeth, are lodged in cavities 

 hollowed out of the jaw bone. They af- 

 terwards rise, and, piercing the gum, ap- 

 pear in the mouth. 



Teeth differ from other bones in pos- 

 sessing no vessels nor nerves in their sub- 

 stance. As they are destined for the 

 merely mechanical functions of triturating 

 the food, such parts would not have been 

 suitable to tin's office. The pain of tooth- 

 ach arises from a nerve, which, with a 



vessel, resides in a hollow, formed in the 

 centre of the fang and body of each tooth. 

 These parts are exposed by the decay. 

 The teeth, in consequence of possessing 

 no vessels, are only affected by chemical 

 and mechanical causes. They do not 

 repair the effects of trituration, nor of 

 accidental injury ; nor do they suffer from 

 any of the diseases which affect other 

 bones. 



There are two sets of teeth ; the first 

 are fewer in number and smaller in size ; 

 as they fall out at a certain age, to make 

 room for other larger ones, they are call- 

 ed deciduous or temporary. The second 

 set lasts throughout life, and are called 

 the adult or permanent set. 



The latter consists of 32 teeth ; 16 in 

 each jaw. There are four incisores or 

 cutting teeth in front ; 2 canini or cuspi- 

 dati, or dog teeth, placed one on each 

 side of the former ; 4 bicuspides behind 

 the last; and 6 molares behind these. 

 From the late period at which the last 

 moluris appears, it is called the dens sa- 

 pientiae, or wise tooth. 



The temporary set consists of twenty 

 teeth ; ten in each jaw. There are 4 in- 

 cisores ; 2 cuspidati ; and 4 molares. 



The permanent teeth are lodged at 

 first in cavities of the jaw, near the roots 

 of the temporary ones; and, as these last 

 are shed, rise up to supply their places. 



The bone of the tongue is called os 

 hyoideS; from its very accurate resem- 

 blance to the Greek y. It consists of a body, 

 two cornua, and two appendices, which 

 are in fact so many separate bits of bone. 



The bones of the trunk consist of those 

 of the spine, thorax, and pelvis. 



The spine consists of twenty-four true 

 or moveable vertebra; ; an os sacrum, and 

 an os coccygis (which indeed is compo- 

 sed of four pieces) ; these last bones, 

 bearing considerable resemblance to the 

 vertebrae, are called sometimes the false 

 vertebrae. 



Each vertebra has a body, which is 

 situated anteriorly, and consists of a cy- 

 lindrical piece of bone ; a perforation be- 

 hind this, in which the spinal marrow 

 runs ; two superior and two inferior arti- 

 culating processes, by which it is joined 

 to the bone immediately above and below 

 it ; two transverse processes, and one spi- 

 nous process, which, projecting behind, 

 forms a sharp ridge, from which the name 

 of spine has been applied to the whole 

 column. 



The vertebrae are divided into three 

 classes, according to their situation : the 

 seven upper ones are called cervical : of 



