9. The adult Cow.—­The upper body color of the adult cow in the National Museum group (see Plate) is a rich, though not intense, Vandyke brown, shading imperceptibly down the sides into black, which spreads over the entire under parts and inside of the thighs.  The hair on the lower joints of the leg is in turn lighter, being about the same shade as that on the loins.  The fore-arm is concealed in a mass of almost black hair, which gradually shades lighter from the elbow upward and along the whole region of the humerus.  On the shoulder itself the hair is pale yellow or straw-color (Naples yellow + yellow ocher), which extends down in a point toward the elbow.  From the back of the head a conspicuous baud of curly, dark-brown hair extends back like a mane along the neck and to the top of the hump, beyond which it soon fades out.

The hair on the head is everywhere a rich burnt-sienna brown, except around the corners of the mouth, where it shades into black.

The horns of the cow bison are slender, but solid for about two-thirds of their length from the tip, ringed with age near their base, and quite black.  Very often they are imperfect in shape, and out of every five pairs at least one is generally misshapen.  Usually one horn is “crumpled,” e. g., dwarfed in length and unnaturally thickened at the base, and very often one horn is found to be merely an unsightly, misshapen stub.

[Illustration:  From a photograph.  Engraved by Frederick Juengling.  BULL BUFFALO. (REAR VIEW.) Reproduced from the Cosmopolitan Magazine, by permission of the publishers.]

The udder of the cow bison is very small, as might be expected of an animal which must do a great deal of hard traveling, but the milk is said to be very rich.  Some authorities declare that it requires the milk of two domestic cows to satisfy one buffalo calf, but this, I think, is an error.  Our calf began in May to consume 6 quarts of domestic milk daily, which by June 10 had increased to 8, and up to July 10, 9 quarts was the utmost it could drink.  By that time it began to eat grass, but the quantity of milk disposed of remained about the same.

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|                       BISON AMERICANUS.                       |
|(Adult cow, eight years old.  Taken November 18, 1886.  Montana.)|
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|          (No. 15767, National Museum collection.)           |
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|                                          | Feet.| Inches.     |
|Height at shoulders                       |   4  |   10        |
|Length, head and body to insertion of tail|   8  |    6        |
|Depth of chest                            |   3  |    7        |