140 THE ARTISTIC ANATOMY OF ANIMALS 



Muscles of the Back 



Trapezius (Fig. 68, i, 2 ; Fig. 6q, i, 2 ; Fig. 70, i, 2). — 

 This muscle, more or less well developed, according to the 

 species, is divided into two portions, of which the names 

 indicate the respective situations — a cervical and a 

 dorsal. 



These two parts, considered in the order in which we find 

 them, take their origin from the superior cervical ligament 

 and from the spinous processes of the first dorsal vertebrae. 

 From these different points the fibres are directed towards 

 the shoulder ; the anterior are, consequently, oblique 

 downwards and backwards, and the posterior are directed 

 downwards and forwards. They are inserted into the 

 scapula in the following manner : the fibres of the dorsal 

 portion are attached to the tuberosity of the spine ; those 

 of the cervical region are also fixed into the same spine, 

 but into a considerably larger surface. 



The cervical portion occupies, in the region of the neck, 

 an area relatively smaller than the corresponding portion 

 of the trapezius in man. This diminished degree of de- 

 velopment results from the absence, complete, or nearly 

 so, of the clavicle in the animals which we are now con- 

 sidering. We remember, that the trapezius of man is partly 

 inserted into the clavicle, and the disappearance of this 

 latter cannot fail to bring modifications in the general dis- 

 position of the corresponding portion of the muscle. There 

 results a disconnection of this latter, and it becomes 

 united to other muscular fibres to form a muscle with 

 which we shall soon have to deal — the mastoido-humeral 

 (seep. 150). 



As specific differences we should add that the trapezius 

 occupies a more or less extensive portion of the median 

 and superior regions of the neck ; terminating at a con- 

 siderable distance from the head in the dog and horse, it, 

 on the contrary, approaches it in the pig and in ruminants. 

 The cervical portion, when it contracts, draws the scapula 

 upwards and forwards, the dorsal portion draws it upwards 



