; MYOLOGY 147 



less recognise its presence ; and in the horse and ox, in par- 

 ticular, it forms an elongated prominence beginning at the 

 level of the scapula, and tapering as it ascends, towards 

 the posterior part of the head. 



Its origins are similar to those which we have already 

 described in the human rhomboid. It arises from the cer- 

 vical ligament and the spinous processes of the foremost 

 dorsal vertebrae ; its fibres converge and pass to the scapula, 

 to be inserted into its superior or spinal border, or into the 

 internal surface of the cartilage of prolongation. 



It assists in keeping the scapula applied to the thoracic 

 cage, and when it contracts, draws the scapula upwards 

 and forwards. 



Taking its fixed point at the scapula, it acts on the neck 

 by its anterior fibres, and extends it. 



We shall soon have occasion to mention this muscle again, 

 in connection with the study of the muscles of the neck. 



The Cutaneous Muscle of the Trunk (Fig. 71). — 

 Immediately beneath the skin which covers the neck, 

 shoulders, and trunk is found a vast cutaneous muscle, 

 analogous to that which, in the human species, exists only 

 in the cervical region. 



This thin muscle, whose function is to move the skin 

 which strongly adheres to it, and in this way to remove 

 from it material causes of irritation (insects, for example), 

 is of considerable thickness in the region of the trunk ; 

 where it constitutes what certain authors have designated 

 by the name of panniculus carnosus. In this region it extends 

 from the posterior border of the shoulder to the thigh, and, 

 in the vertical direction, from the apices of the spinous 

 process of the dorso-lumbar vertebrae to the median line of 

 the abdomen. 



Arising above from the supraspinous ligament of the dorso- 

 lumbar and sacral regions (except in the carnivora ; see 

 below) by an aponeurosis which, posteriorly, covers the 

 muscles of the hind-limbs, its fibres are directed to the elbow, 

 on which they are arranged in two layers : a superficial, 

 which becomes continuous with the panniculus muscle of 

 the shoulder ; and a deep, which passes on the inner 



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