OSTEOLOGY. 49 



to the atlas are attached xo; to the axis, xt ; to the remaining 

 (anterioriy) 10, (posteriorly) 22. [The vertebrae are developed 

 from 3 centres by ossification, the first appearing at 6th week ; 

 at sixteen 4 secondary centers appear, and at twenty-one a 

 circular plate for superior and inferior surfaces of body. A 

 few exceptions, as atlas (2 primitive centers), axis (6), jth 

 cervical and the lumbar (5).] 



Sa'crna : triangular, anterior and posterior foramina, lateral 

 masses, laminae, tubercular transverse processes, promontory, 

 sacral canal and groove, auricular surface. Articulations (4); 

 innominate, 5th lumbar, coccyx. Musc!es t (5) ; pyrifcrm, 

 coccygeus , glutaeus maximus, erector spin, latissimus dorsi. 

 35, 8th week.] 



Ccc'CyX : cornua. Articulation, (i)j sacrum. Muscles, (4) j 

 coccy^eus, glutaeus maximus, sphincter and levator am. [4, 

 birih to puberty.] 



Occi^lta'lo: superior and inferior curved lines, crest, pro* 

 tuberancc, foramen magnum, condyles, basilar and jugular 

 processes, pharyngeal spine, anterior and posterior conc ? y*- 

 loid foramina ; fossae cerebri et cerebelli, torcula protuberance, 

 grooves for occipital, lateral, inferior petrosal, superior longi- 

 tudinal sinus and medulla, jugular fossa. Artie. (6^; 2 parietal^ 

 a temporal, sphenoid, atlas. Muse. (12) ; occipito- fronta'.is, 



* trapezius, sterno-cleido-tnastoid, complexus, tplenius capitis^ 

 obliquus superior, rectus Posticus major and minor t rcctu* 

 lateralis t rectus anticu s major and ntinor t superior pharynr 



- geus, constrictor. [4, xoth week.] 



Pariotale: eminence, foramtn, temporal ridge; Pacchio- 

 nian dcpres ions> mi ^dle meningeal groove, superior lonitu 

 dinr.l and lateral sinus. Artie. (5) ; fellow, occipital, frontal, 

 temporal, sphenoid. Muse, (i) ; temporal, [i.] 



Pronta'e: eminence, supercilliary ridges, external and 

 internal angular processes, supra-orbital notches and arches, 

 temporal ridges and fossae, nasal eminence and spine; orbital 

 plates, lachrymal fos^a, pulley depression, ethmoid notch f 

 anterior ethmoid foramina, foramen caecum, meningealgroovcs f 

 Pacchionian depressions, frontal and superior longitudinal 

 sinus (frontal suture). Artie. (12)52 parietal, sphenoid, cth* 

 moid, a nasr.l, 2 superior maxillae, 2 lachrymal, 2 malar. Muse. 

 (3 pr.); corrugator supercilii, orbicularis palpebrarum, tempo* 

 ral. [a.] 



TeapOPilft zygoma, articular eminence, glenoid fossa, 

 Glasserian fissure, vaginal, styloid, mr,stoid and auditory 

 processes, mastoid foramen, superior and inferior petrosal 

 4 



