286 



REPTILIA. 



The last named muscle (Sham' 



ungenbein- 



muskel) (fig. 208, 7) arises partly from the os- 

 Fig. 207. 



Itfitscles of Salamander terrestris. 

 pubis and partly from the outer border of the 



Y-shaped pelvic cartilage, whence it rims 

 forward along the whole length of the abdo- 

 men, enclosed in a sheath, formed between the 

 internal and external oblique muscles of the 

 abdomen as far as the throat, where it is 

 inserted into the middle cornea of the os- 

 hyoides. 



The rectus abdominis (fig. 208, 8) takes its 

 origin entirely from the Y-shaped pelvic car- 

 tilage, and, first attaching itself to the trian- 

 gular lower rudiment of the sternum, over 

 which it passes, it becomes again connected 

 with the upper transverse piece of the ster- 

 num, from whence it sends a slip forwards to 

 be inserted into the centre of the lower jaw : 

 this last portion represents the genio-hyoi- 

 deus. 



In its course, this muscle is divided by 

 several tendinous intersections. It is, more- 

 over, attached with some firmness to the 

 pericardium, in the neighbourhood of which 

 it gives off two additional slips of muscle, one 

 of which passes obliquely outwards to join 

 the pubo-hyoid ; the other (10) runs to 

 be inserted into the scapula, becoming like- 

 wise connected with the scapulo-humeral 

 articulation. 



The mylo-hyoideus (fig. 208, 1 1) fills up the 

 entire space betwen the arches of the lower 

 jaw, from the angle of which, likewise, arise 

 two cutaneous muscles (fig- 207, 12) and (fig. 

 208, 13), one of which extends into the skin of 

 the inferior and anterior region of the neck, 

 whilst the other mounts backwards and out- 

 wards to be similarly inserted into the skin 

 upon the sides of the cervical region. A 

 muscle (fig. 208, 14) passes from the lower jaw 

 near its symphasis, to be inserted into the 

 extremity of the anterior cornu of the os- 

 hyoides ; whilst a second slip (15) passes 

 from the anterior to the central cornu of the 

 latter bone. 



Muscles of the Extremities. The pectoralis 

 major (fig. 208, 16) consists of two portions, 

 one of which, 16 a, represents the clavicular 

 portion in the human subject ; it entirely 

 covers the lower surface of the shovel-shaped 

 clavicle, so that it seems to form a distinct 

 muscle. 



The following muscles are immediately re- 

 cognisable from their position : The latissi- 

 mus-dorsi (fig. 207, 1 1) ; the levatores-scapulae 

 (fig. 207, 18 and 19) ; a muscle (20), 

 the office of which is to draw the shoulder 

 forwards. This muscle is derived from the 

 sides of the occiput and anterior cervical 

 vertebra, and extends to be inserted into the 

 shoulder-blade near its articulation. The 

 serratus magnus anticus (fig. 208, 21) consists 

 of only two small slips derived from the 

 transverse processes of the second and third 

 vertebras of the neck, and connected with the 

 great lateral muscle of the trunk. The 

 shoulder likewise possesses a muscle (22) 

 that represents both the supra and infra 

 spinatus, and a subscapularis occupying its 

 usual position. 



The muscles of the humeral region are the 

 representative of the biceps, and brachialis 



