Even an observer not acquainted with the anatomy of this region who watches closely a horse in action cannot fail to notice how at every step taken there is a marked jolt of the neck produced in the neck by the impact of its hoofs with the ground and in supporting its heavy skull. I have computed several times the number of jolts that the neck of a trotting horse sustains, in my numerous rides behind various horses, during many hundreds of miles, and have reckoned the number which occur in a horse trotting for an hour, at the usual rate at which a doctor travels. This is on the average 6,000, and of course the numbers of jolts in walking, cantering, and galloping vary according to these different paces. But a great deal more of movement of the head and neck is observed beside the jolt at every step. See how the animal tosses up its head, twists it to this and that side for the mere _joie de vivre_ when it is fresh, or, even when hindered by blinkers,[47] how he turns his head to look at every passing object in the road with his ancestral caution, how he will pass contemptuously a great horse-waggon or even now a villainous-looking motor lorry, but will peer at a beggar woman sitting beside the road, or a heap of stones, or a yapping cur! All this vivid muscular work of a horse’s head and neck hardly ceases while he is in action and at any rate not till he is dead beat, and the higher the courage and breeding of the horse the more frequent and brisk are his movements. Is it possible to conceive a region of the body of any large mammal where more numerous, varied, and powerful action of underlying muscles can be found playing their ceaseless tricks on the sober normal slope of hair in the skin which covers them? If there be any region approaching this I have not found it. [47] Blinkers ought long ago to have gone the way of bearing-reins for draught horses. If a riding horse does not need them, no more need a draught horse be thus insulted, for very little intelligence and patience on the part of their drivers would have educated their excellent brains into indifference towards startling objects. [Illustration: Fig. 3.--Superficial muscles concerned in the movements of the head and neck of the horse.] [Illustration: Fig. 4.--Deeper layer of the muscles concerned in the movements of the head and neck of the horse; the scapula removed.]