64 THE HORSE IN MOTION. 



they serve. This is the special function of the trapezius (g, g, 

 Plate III.). It is so perfectly represented in the plate that it requires 

 but little description. It is divided into two parts by the spine of 

 the scapula (see Plate II.), into which both divisions are inserted 

 along with a band of the ligament of the neck, which seems to be 

 sent off for the purpose of aiding with its passive force the trape- 

 zius in holding the limb to its place. The upper insertions or origins 

 of both divisions are in the same ligament of the neck, or yellow cord, 

 as it is well called by hippo-anatomists. This cord is distinguished 

 not only by its color but by its elasticity from all other ligaments. 

 It seems to be, indeed, a special contrivance to afford means for the 

 attachment of important muscles when the spines of the vertebra 

 are too remote to afford it. It extends from the head to the strong 

 spines of the dorsal vertebra, where it becomes merged into ordinary 

 ligament. It may be that the branch of this cord that is inserted 

 into the spine of the scapula is itself sufficient to support the weight 

 of the anterior limb, and that the muscle under consideration is used, 

 the two parts acting alternately, to aid in locomotion, exerting their 

 forcj at the upper or cartilaginous extremity of the scapula and above 

 the centre of motion or attachment of the serratus ; but however that 

 may be, its aid in locomotion cannot be great, as its entire weight 

 does not exceed two ounces. Its thickness does not vary much from 

 half an inch. It is separated from the skin only by the general 

 aponeurosis, or fibrous covering described in a former chapter, and 

 which has been dissected away from the whole body in the subject 

 of the drawings. 



When the trapezius is removed, the rhomboideus is brought into 

 view. This muscle is so named from the corresponding muscle in 

 man, in whom it is in the form of a rhomboid ; and if the name were 

 limited to the muscle so far as it corresponds to that in man there 

 could be no objection to it, but since Cuvier's time it has been made 

 to embrace another muscle, the levator anguli scapula (Plate IV., /) 

 To this union in the horse there can be no objection, anatomically 

 or mechanically; but when so united they are no more like a rhom- 

 boid than a tent-pin, and the name of levator anguli scapulae should 



