MYOLOGY 133 



extends as far as the sixth ; in the dog, it is attached to the 

 two first sternal pieces only — that is to say, as far as the 

 third costal cartilage. Moreover, in the latter, as in the 

 cat, the two portions which we have indicated are less 

 readily distinguished. 



The great pectoral, by its contraction, draws the 

 fore-limb towards the middle line — that is to say, ad- 

 ducts it. 



The Pectoralis Minor (Fig. 67, 6 ; Fig. 68, 8 ; Fig. 69, 

 II ; Fig. 70, 12, 26). — This muscle, also called the deep 

 pectoral, is, in animals, larger than the superficial pectoral, 

 therefore certain authors prefer to give to this muscle and 

 the preceding one the names of deep and superficial pectoral 

 respectively. This nomenclature is evidently legitimate, 

 and conforms more to reality, since it does not bring in 

 the notion of dimensions which here is found in contradic- 

 tion to nomenclature ; but, in order to establish more 

 clearly the parallelism with the corresponding muscles in 

 man, we think it better, nevertheless, to give them the 

 names by which it has been customary to designate them 

 in connection with the latter. 



We will recall at the outset that the lesser pectoral 

 muscle in man is completely covered by the great. In 

 animals this is not the case ; the lesser pectoral being 

 very highly developed, projects beyond the great pectoral 

 posteriorly, and occupies to a greater or less extent the 

 inferior surface of the abdomen. 



It also consists of two parts : one anterior, which we 

 designate by the name of sterno-prescapular ; the other, 

 posterior, bearing that of stev no-humeral.'^ 



The sterno-prescapular muscle, being covered by the 

 sterno-humeral, has little interest for us. It arises from 



* This division of the pectorals certainly complicates the nomenclature 

 of these muscles ; nevertheless, it introduces no insuperable difficulty 

 from the mnemonic point of view. But where the studj^ becomes less 

 profitable, and comparison with the corresponding muscles in man 

 more complicated, is in adopting the nomenclature of Bourgelat. 

 Indeed, the great pectoral is designated by this author the ' common 

 muscle of the arm and forearm,' while the lesser pectoral (or deep 

 pectoral) is called^ the ' great pectoral ' in its sterno - trochinian and 



