The fine, soft hair upon the hinder part of a cow's udder for the most part turns upward. This upward-growing hair extends in most cases all over that part of the udder visible between the hind legs, but is occasionally marked by spots or mere lines, usually slender ovals, in which the hair grows down. This tendency of the hair to grow upward is not confined to the udder proper; but extends out upon the thighs and upward to the tail. The edges of this space over which the hair turns up are usually distinctly marked, and, as a rule, the larger the area of this space, which is called the "mirror" or "escutcheon," the more milk the cow will give, and the longer she will continue in milk.
That portion of the escutcheon which covers the udder and extends out on the inside of each thigh, has been designated as the udder or mammary mirror; that which runs upward towards the setting on of the tail, the rising or placental mirror. The mammary mirror is of the greater value, yet the rising mirror is not to be disregarded.

License information: nan
MPAA: G
Go to source: http://www.gutenberg.org/files/8195/8195-h/8195-h.htm#10