SCAPULA. 127 



the lower part. The vertebral border presents an anterior lip, a posterior lip, and 

 an intermediate space. The anterior lip affords attachment to the Serratus mag- 

 nus ; the posterior lip, to the Supra-spinatus above the spine, the Infra-spinatus 

 below ; the interval between the two lips, to the Levator anguli scapulas above 

 the triangular surface at the commencement of the spine ; the Rhomboideus minor, 

 to the edge of that surface ; the Rhomboideus major being attached by means of 

 a fibrous arch, connected above to the lower part of the triangular surface at the 

 base of the spine, and below to the lower part of the posterior border. 



Of the three angles, the superior, formed by the junction of the superior and 

 internal borders, is thin, smooth, rounded, somewhat inclined outwards, and gives 

 attachment to a few fibres of the Levator anguli scapula muscle. The inferior 

 angle, thick and rough, is formed by the union of the vertebral and axillary 

 borders, its outer surface affording attachment to the Teres major, and occasionally 

 a few fibres of the Latissimus dorsi. The anterior angle is the thickest part of 

 the bone, and forms what is called the head of the scapula. The head presents 

 a shallow, pyriform, articular surface, the glenoid cavity (7x^57, a superficial 

 cavity; 8o 5 , like)] its longest diameter is from above downwards, and its 

 direction outwards and forwards. It is broader below than above ; at its apex is 

 attached the long tendon of the Biceps muscle. It is covered with cartilage in 

 the recent state; and its margins, slightly raised, give attachment to a fibro- 

 cartilaginous structure, the glenoid ligament, by which its cavity is deepened. 

 The neck of the scapula is the slightly depressed surface which surrounds the 

 head ; it is more distinct on the posterior than on the anterior surface, and below 

 than above. In the latter situation it has, arising from it, a thick prominence, 

 the coracoid process. 



The Coracoid process, so called from its fancied resemblance to a crow's beak 

 (xopa|, a crow ; 8oj, resemblance), is a thick curved process of bone, which arises by 

 a broad base from the upper part of the neck of the scapula ; it ascends at first 

 upwards and inwards ; then, becoming smaller, it changes its direction and passes 

 forwards and outwards. The ascending portion, flattened from before backwards, 

 presents in front a smooth concave surface, over which passes the Subscapularis 

 muscle. The horizontal portion is flattened from above downwards ; its upper 

 surface is convex and irregular ; its under surface is smooth ; its anterior border 

 is rough, and gives attachment to the Pectoralis minor ; its posterior border is also 

 rough for the coraco-acromial ligament, while the apex is embraced by the con- 

 joined tendon of origin of the short head of the Biceps and Coraco-brachialis 

 muscles. At the inner side of the root of the coracoid process is a rough depres- 

 sion for the attachment of the conoid ligament, and, running from it obliquely 

 forwards and outwards on the upper surface of the horizontal portion, an elevated 

 ridge for the attachment of the trapezoid ligament. 



Structure. In the head, processes, and all the thickened parts of the bone, it 

 is cellular in structure, of a dense compact tissue in the rest of its extent. The 

 centre and upper part of the dorsum, but especially the former, is usually so thin 

 as to be semi-transparent; occasionally the bone is found wanting in this situation, 

 and the adjacent muscles come into contact. 



Development (fig. 86). By seven centres ; one for the body, two for the coracoid 

 process, two for the acromion, one for the posterior border, and one for the inferior 

 angle. 



Ossification of the body of the scapula commences about the second month of 

 foetal life, by the formation of an irregular quadrilateral plate of bone, imme- 

 diately behind the glenoid cavity. This plate extends itself so as to form the 

 chief part of the bone, the spine growing up from its posterior surface about the 

 third month. At birth the chief part of the scapula is osseous, the coracoid and 

 acromion processes, the posterior border, and inferior angle, being cartilaginous. 

 About the first year after birth, ossification takes place in the middle of the 

 coracoid process ; which usually becomes joined with the rest of the bone at the 

 time when the other centres make their appearance. Between the fifteenth und 



