382 MUSCLES. 



The Subclavius, 



Is a small muscle, placed immediately under the clavicle. It 

 arises from the cartilage of the first rib, and is inserted into the 

 inferior face of the clavicle, from near the sternum, to the co- 

 noid ligament, which connects the coracoid process and the 

 clavicle together. It draws the clavicle downwards.* 



The Serratus Magnus, or Serratus Major Anticus, 



Is a broad muscle, lying on the sides of the ribs, between them 

 and the scapula, and beginning at a line anterior to their middle. 

 It arises from the nine upper ribs by fleshy digitations, the su- 

 perior one of which seems almost like a distinct muscle: the 

 five lower are connected to the obliquus externus abdominis, 

 the digitations of the two muscles inter-locking with each other. 

 The fibres converge, and are inserted into the base of trie scapula 

 its whole length. Its action is to draw the scapula forwards. t 



The Inter costales, 



Fill up the spaces between the ribs. There are two in each 

 space, of which the external arises from the transverse process 

 of the vertebra, and from the inferior acute edge of the rib, 

 from its head almost to its cartilage, and is inserted into the su- 

 perior rounded edge of the rib below for the same distance, its 

 fibres passing obliquely forwards and downwards. The inter- 

 nal intercostal arises from the inferior edge of the rib, beginning 

 at the sternum, and extends backwards to the angle of the rib; 

 it is inserted into the superior rounded edge of the rib, below, 



which arises from the first and second ribs, and is inserted into the coracoid pro- 

 cess; whereby a striding analogy with birds is established. Another variety has 

 also been observed in the existence of a fasciculus, which comes from the upper 

 rib, and which, covered by the little pectoral muscle, is inserted into the capsular 

 ligament of the scapulo-humeral articulation. 



* Varieties. Sometimes two muscles exist; a bursa mucosa is formed between 

 its tendon and the cartilage of the first rib. 



t Varieties. Sometimes, it has ten or eleven origins ; the upper origin is defi- 

 cient; the latter is so distinct that it may pass for a particular muscle; a wide 

 gap exists in the middle of the muscle, dividing it into two distinct parts. 



