Examples of the Effects of Pressure.

Looking at the figures of a horse harnessed, and another without harness, Figs. [49] and [50], one sees on the latter eight different regions where patterns of hair, not found in the horse normally, are displayed. They are as follows:—

A.The under surface of the neck.Pattern due to the collar.
B.The hamstring region.Pattern due to the kicking strap.
C.The hollow corresponding to what we should call the armpit.Pattern due to strap of saddle.
D.The coccygeal or tail-region.Pattern due to the crupper.
E.The side of the neck.Pattern due to the reins.
F.The shoulder.Pattern due to the shaft.
G.The side of the face.Pattern due to strap of head stall.
H.The border of the neck under the collar.Pattern due to collar.

All these aberrations from the normal are rare except the first (A), and all are based on the observa­tion and drawing of individual specimens which I brought before the Zoological Society and the details of which are given in a note on page [129]. The rarer seven examples are described because taken together they show what the pressure of harness can do at certain points where its pressure is adequate, and they are all situated where they might be expected if such a force could effect hair-changes, and there are none of them found on areas where neither pressure nor underlying muscular traction can act efficiently. Thus in many thousands of horses I have never seen a hair-pattern on the middle of the flank or the under surface of the abdomen or the middle of the back or gluteal region or on the fore or hind legs. This negative evidence is of great importance, and must be taken for what it is worth. I may venture to remind the reader that every one of these phenomena is an artificial product of man’s treatment of the horse. They come thus under the category of undesigned experiments.

The only one of the eight artificial patterns, which as a rule are in the form of a whorl feathering and crest, that needs, further close attention is the pattern A, produced on the under surface of the horse’s neck by the collar, and this will be examined separately.

Fig. 49.—Domestic horse, fully harnessed.