100 THE EXTERIOR OF THE HORSE. 



vexity of the inferior border. Many horses showing this conformation 

 have, in front of the withers, a distinct depression. Most of them 

 also hold the head in a horizontal direction, as we have indicated. 



In a general way, all these forms are so much more compatible 

 with the velocity of the gait the more the head is carried in advance 

 of the base of support and, consequently, as the cervical trunk is less 

 convex along its superior border. The pyramidal and reversed forms 

 remove the head farthest from the body and denote the greatest speed. 

 On the contrary, the arched and the swan-neck, by their tendency 

 to curve the vertebrae in the shape of an S, diminish the length of 

 the neck, move the centre of gravity backward, and are more favor- 

 able to its elevation and depression as well as to the lateral displace- 

 ment of the trunk. They also offer advantages in the saddle-horse, 

 in which grace, brilliancy, rapidity, and extent of movement are pre- 

 ferred. 



These conformations can be acquired by means of mechanical con- 

 trivances and appropriate dressing. All horsemen are in the habit of 

 making the necks of their horses supple by obliging them to execute 

 progressively the movements of extension, flexion, and lateral inclina- 

 tion. The utility of such suppleness is easily understood, since this 

 kind of functional gymnastics has no other purpose than to habituate 

 the animal to use this balance so powerful and so useful with dex- 

 terity and rapidity, and thus overcome the resistance of the head. We 

 shall, farther on, see that these cervical gymnastics, carried to an ex- 

 treme, will prove prejudicial in certain cases, while, when well employed, 

 their efficacy becomes incontestable in certain others. 



Direction or Carriage. Independently of the particular forms 

 which it assumes, the neck also carries itself in several directions 

 relative to the vertical line. We shall consider three varieties : 



1st. The vertical, or, more properly, an approximation to the 

 vertical. In this attitude, which constitutes a point of beauty and 

 indicates energy, the head is easily sustained, the animal is easy on the 

 reins and the bit, and the movements of the shoulders are free and 

 extensive (Fig. 32). 



Let mn and OJ5, for illustration, represent the directions of the 

 shoulder and the neck respectively. The extensor muscles and the 

 mastoido-humeralis will be schematically represented by the lines Bm 

 and Bn. The latter, it will be plainly seen, has a more considerable 

 length, and therefore a greater amplitude of contraction to elevate the 

 scapulo-humeral angle and increase the arc described by the forefoot. 

 We see, moreover, that the weight of the head, represented by the line 



