210 
ILLUSTRATED STOCK DOCTOR. 
no definite direction. They present themselves irregularly , with zigzag 
lines, knotted, and more or less oblique. They are never of very largo 
size, except in cows that give large quantities of nnlk. 
The veins of the twist directed from above downward, forming a wind- 
ing line, interspersed with knots, resemble those of the udder in not 
being visible either in heifers or in cows of only fair milking quality. Wo 
cannot ascertain their presence in any but very good cows. 
Of all the marks of abundant milk secretion, the best, and in fact the 
only infallible marks, are furnished by the veins of the twist and of tho 
udder. To estimate them correctly it is necessary to take into account 
the state of the cow in respect to flesh, the thickness of skin, food, ability 
to stand fatigue, heat ; all the circumstances, in fact, which cause vari- 
ations in the general state of the circulation, and in the dilation of tho 
veins. It is necessary, moreover, to recollect that in both sexes all tho 
veins are larger in the old than in the young ; that the veins which encir- 
cle the udder arc those which, if the cows are in milk, vary most accord- 
in'*- to the ago of the animal. Small when the animal is young, they 
continue to increase in size until after tho cow has had several calves. 
when they come to their full development. 
This proportion between the size of the veins and the milk secreted, Is 
observed in all females without exception. The size of the veins and 
their varicose state being due to the blood attracted by the increased 
activity of the milk-glands, is not only the sign, but also the measure, of 
this activity— this connection. In fact, this connection is so close that, if 
the glands do not give an equa? quantity of milk, tho larger veins are on 
the side of the udder which gives the largest quantity. 
The length of time during which milk is given corresponds with tho 
activity of the organs which supply it. Cows which give most milk a 
day, also give it the longest; and hence, if no special mark is perceived, 
i wc can judge much of the duration of milk by the marks which determine 
its quantity. It may therefore be accepted that as a rule an abundant 
milker may be expected to give a long continued flow of milk. 
Judging Ago by the Teeth. 
For the reason that the age of cattle can only be approximately judged 
by the horns, and in consequence of the liability to error, and especially 
the doctoring of the horns by the use of the file, sand paper and oil, wo 
^ive a chart, showing from the cuts presented, the ages of cattle, lrotn 
birth until they are five years old, when the teeth are fully dcvelopcc , 
and also the appearance of the teeth at ten years of age. Thus at birth, 
it will be seen, there will be but two central teeth , figure 1 ; at two weeks 
it will have four teeth, figure 2 ■, at three weeks it will have six teet , 
