44 



ANATOMY OF VERTEBRATES. 



20 



the weight of the deep chest of the Ruminants, the interposition 

 of the elastic cartilages between the upper attachments of the 

 muscles and the capitals of the bony columns of the two fore-legs 

 is attended Avith the same advantage as is obtained by slinging the 

 body of a coach upon elastic springs. 



The main body of the 'pectoralis major,' fig. 18, is, rises from 

 the sternum and ensiform cartilage, the fibres converging to the 



O y O O 



tendon inserted in the outer tuberosity of the humerus : the an- 

 terior derivative from this muscle, effecting 

 the crossing of the fore-limbs, is present in 

 Ruminants as in Solipeds and Cetaceans. Two 

 muscles converge to an insertion answering to 

 that of the f deltoid ; ' one is the superficial 

 portion of the ' masto-humeralis,' fig. 18, 8, 

 fig- 19, 11 ; the other, ib. u, arises from the 

 spine and post-spinal fossa of the scapula : the 

 latter is the proper homologue of the ( deltoid.' 

 The ( supra- or pre-spinatus ' is shown at 

 i, figs. 20 and 21 ; it is inserted by a double ten- 

 don into the fore and inner tuberosities of the 

 humerus : the ' infra- or post-spinatus,' fig. 

 20, 2, has a single strong insertion into the 



JD ~ 



outer tuberosity. The insertion of the ' teres 

 major ' is seen at fig. 20, 3. 



The subscapularis, fig. 21, 2 and 2 X , con- 

 sists of two chief masses, and corresponds in 

 length and narrowness with the bone from 



o 



which it originates ; it consequently produces, 

 like the muscles on the opposite surface of the 

 scapula, more rapid and extensive motion ot 

 the humerus, to the inner tuberosity of which 

 it is attached. The s coraco-brachialis,' fig. 20, 

 8, arises from the tuberous representative of 

 the coracoid ; its insertion into the humerus ex- 

 tends down to the inner condyle. The ' biceps 

 brachii,' fig. 21, 10, shows an origin from the 

 coracoid as well as the chief one from above 

 the glenoid cavity of the scapula. It is in- 

 serted into the radius, below the usual tuberosity, and also sends a 

 strip of tendon to the antibrachial aponeurosis. In the Camelidce 

 the tendon of origin is double, but approximated, and encloses a 

 sclerous sesamoid as it passes over the head of the humerus. The 

 * brachialis internus ' rises from the neck of the humerus ; its in- 



IV 



?Ju<rles of fcirc-liinl), Cow ; 

 from die outer (iiluar.) side 



IV. 



