The main facts of the anatomy of the horse’s neck must be referred to here, so that a better picture may be obtained as to the powerful forces which are found in conflict during the locomotive life of the animal. Fig. 3 shows the superficial layer of muscles concerned in the actions of its head and neck, and the manner in which adjoining muscles diverge from one another should be noted. Fig. 4 gives the deepest layer of neck-muscles, the shoulder-blade having been removed, and Fig. 5 the immensely strong _ligamentum nuchae_, of yellow elastic tissue, which extends from the base of the skull to the great projecting spinous process of the lowest cervical and second and third dorsal vertebræ. [Illustration: Fig. 5.--Ligaments and tendons supporting the head and neck of the horse.] There are here indeed great forces for conflict--_first_ a layer of strong superficial muscles, _second_ a layer of smaller muscles which has not been figured, _third_ a deep layer of muscles, and _fourth_ a powerful, widely-spread and strongly-attached mass of dense elastic tissue, adapted for supporting the head without muscular exertion, but by its elasticity allowing a downward jerk of the head and neck at every step. It is an exceedingly important structure for a domestic horse. The Normal Arrangement of Hair. So much for the active part played by a horse’s neck and head, and for the simpler anatomical facts of the region involved. Before proceeding to describe the results of these as seen in the hair, it is well to make sure of a point which a critic might raise. “How do you know,” says he, “that some of the variations in this highly variable region of the hair are not normal. What is the normal type here?” A very easy answer to this is found by studying, not only any Ungulate known, except the Gnu, but more particularly all wild Equidæ; and this reveals the fact that in all this series the normal slope of hair prevails here, that is to say, an even trend from head to shoulder. Variations in others, indeed, hardly exist, and I may add that the absence of variations here is a strong piece of negative evidence in my favour, for no Ungulate comes near the domestic horse for amount and activity of locomotion, which is indeed his _raison d’être_. He is the only one that has invented new patterns. But a little direct evidence can be brought which clinches this argument from inference based on ancestry. I made an examination, at the stables of Messrs. Tilling, at Peckham, of 100 consecutive specimens of hackney, for the purpose of ascertaining the proportion in that group of those that showed the normal slope on the neck to those with variations. In 62 of these the normal existed on both sides of the neck, 18 Normal on one side, and in the remaining 20 there were variations on both sides. If 100 specimens of horses contain 80 with one side and 62 with both normal the previous inference requires no further support. Fourteen Varieties.