Fig. 40.
Fig. 41.
Fig. 42.
In calves the mirrors show the shapes they are afterwards to have, only they are more contracted, because the parts which they cover are but slightly developed. They are easily seen after birth; but the hair which then covers them is long, coarse, and stiff; and when this hair falls off, the calf’s mirror will resemble that of the cow, but be of less size.
With calves, however, it should be stated, in addition to what has already been said, that the milk-mirrors are more distinctly recognized on those from cows that are well kept, and that they will generally be fully developed at two years old. Some changes take place in the course of years, but the outlines of the mirror appear prominent at the time of advanced pregnancy, or, in the case of cows giving milk, at the times when the udder is more distended with milk than at others.
The classification adopted by Magne appears still further to simplify the whole method, and to bring it within the easy reach and comprehension of every one who will examine the figures and the explanations connected with them. He divides cows, according to the quantity they give, into four classes: First, the very good; second, the good; third, the medium; and fourth, the bad.
In the first class he places cows both parts of whose milk-mirror, the mammary and the perinean, are large, continuous, uniform, covering at least a great part of the perineum, the udder, the inner surface of the thighs, and extending more or less out upon the legs, as in [Figs. 29] to [33], with no interruptions, or, if any, small ones, oval in form, and situated on the posterior face of the udder, [Figs. 29], [30], and [32].