Behind the level of the horns the normal or backward slope proceeds until the middle of the length of the neck is reached, when it encounters transversely a sharp upstanding crest and beyond this the hair is directly reversed from a point over the shoulders, and here a whorl is found. From this point the stream returns to its ancient and normal course and so passes to the tail. When the base of the tail is reached a very significant and apparently whimsical arrangement of the hair down the centre of the tail is observed. This consists in a line of stiff hairs which stand up at right angles to the surface of the tail, and it gradually passes into the normal again when the more muscular part of the tail is passed. I should add here that the crest and reversed hair on the back are common to many wild ungulates of this ruminant group, and a good example of it is seen in an antelope, Oryx Beisa, which I figured and described in a paper at the Zoological Society of London. Arrangements of its hair so audacious as these need explanation, and it is found in the mode of life of the cow. So large a part of its daily life is spent in the business of grazing with her muzzle close to the ground, during which the neck of the animal is constantly stretched downwards from the back at the level of the shoulders, that the skin, which is very loose in this and most other portions of its body, is dragged upon to allow of the extreme flexion of its neck. This traction is for all this time acting against the normal or backward slope of the hairs, and has given rise to this victory of a new force through a thousand generations. It is equally clear that a mechanical explanation of the line of erect hairs on the first nine or twelve inches of the tail is forthcoming, for one has only to watch a cow standing on a hot day, undergoing her torment of flies, to see it writ large. Very strong little muscles are found at the base of the tail, those along the more free portion becoming smaller and smaller until they disappear towards the tip. These give a powerful flicking action to the long heavy tail and I once made some observations as to this on a number of cows which were grazing in summer on a comparatively cool wind-swept hillside in the western end of the Isle of Wight. I watched several cows on different occasions and found that one would flick her tail 348 times and another 1082 times per hour. Giving these cows an eight hours’ working day, “working” for their living in grazing and ruminating by turns, one gains a vivid idea of the number of times per diem these powerful muscles of the tail contract. If we call it a day of four hours of grazing and four of ruminating, for the sake of argument, we get 1392 to 4328 flicks of the tail each day in the time of flies, leaving out of account the casual flicks in which she would indulge when flies were not tormenting her. It is hardly necessary to point out