Effects of Pressure by Harness.

Second.—The next stage of the inquiry demands that one should show the patterns to be due to pressure.

Fig. 51.—Roan cart horse, exam­ined 25th Sep­tem­ber, 1914. On left side of middle line of the under surface of the neck a short reversed area three inches long, lying ver­tic­al­ly—none on the right side.

Fig. 52.—Grey cart horse examined 25th Sep­tem­ber, 1914. Long central feather­ing (F) proceed­ing ver­tic­al­ly upwards in middle line of neck from whorl (W) and ending in a crest (C) at the upper limit of region, through which the collar can move in active loco­motion.

In the accompanying drawings the under surface of the neck and the chest of each horse is shown with the collar in place, the centre portion of which is cut out so as to show the arrangement of hair beneath, and some of the varieties are seen to extend for several inches above it. In considering this process one ought to watch the way in which the collar of a horse, as a rule, is seen to move up and down as he trots, for in most cases, except in cart-horses, the collar fits very loosely and is easily jolted upwards. This will explain why the patterns often extend upwards above the proper position of the collar, but it must also be remembered that never have I found a pattern higher up in the middle of the neck than a loose collar can reach when jolted. (Close to the lower jaw there is a whorl or pattern often found which belongs to a different category, and is not to be confused with the patterns in question.)

Fig. 53.—Brown hackney, examined 9th October, 1914. Small reversed area of hair lying under collar in middle line of under surface of neck, passing ver­tic­al­ly upwards three inches long, in cen­tral posi­tion.

Fig. 54.—Brown cart horse, examined 25th October, 1914. Whorl, feather­ing and crest (W F C) in middle line of under surface of neck, begin­ning below where the collar should lie in usual posi­tion.

In the conditions described there is present exactly that frequent pressure of a moving body against the growing hair, which is requisite to produce changes in its direction, as well as the more fixed pressure of the collar when it is fitting firmly against the lower part of the neck.

By way of confirma­tion of the view that this is the modus operandi one has only to point to the other seven regions shown in Figs. [49] and [50], in which the connec­tion between the pressure of harness and the produc­tion of a new pattern is beyond all doubt one of cause and effect.

Fig. 55.—Brown cart horse, examined 25th October, 1914. Whorl, feather­ing and crest (W F C) in middle line of under surface of neck begin­ning under­neath collar and proceed­ing ver­tic­al­ly up­wards for six inches.

Fig. 56.—Bright bay pony, examined 29th October, 1914. Very mus­cu­lar neck. On under surface on each side a wide curv­ing stream of hair pass­ing towards middle line and join­ing in a cen­tral upward stream end­ing above in a tuft (T).