SELECTION OF MILK COWS. 379 



udder, in not being visible either in heifers or in beasts of mid- 

 dling quality. We cannot ascertain their presence in any but 

 very good cows. 



"Of all the marks of abundant milky secretion, the best, and 

 indeed the only infallible marks, are furnished by the veins of 

 the twist and of the udder. But, although the surest, they are 

 not absolutely decisive. 



"To estimate them, it is necessary to take into account the 

 state of the cows in respect of flesh, the thickness of the skin, 

 food, general activity, fatigue, journeys, heat; all the circum- 

 stances, in short, which cause variations in the general state of 

 the circulation, and in the dilatation of the veins. It is neces- 

 sary, moreover, to recollect that in both sexes, all the veins are 

 larger in the old than in the young; that the veins which encir- 

 cle the udder are those which, if the cows are in milk, vary 

 most, according to the different periods of life; though scarcely 

 apparent in youth, they are of considerable size, when, after 

 several calvings, the operation of milking has given the gland 

 its full development. 



"This proportion between the size of the veins and the milk 

 secreted, is observed in all females without exception. The 

 largeness of the veins and their varicose state, being a conse- 

 quence of the quantity of blood attracted by the activity of the 

 milky glands, is not only the sign, but alst> the measure of this 

 activity; the connection between the two phenomena is such, 

 that, if the glands do not give an equal quantity of milk, the 

 larger veins are on the side of the gland which gives the larger 

 quantity. 



DURATION AND QUALITIES OF THE MILK. MARKS FOR ASCER- 

 TAINING HOW LONG MILK IS GIVEN. 



"The length of time during which milk is given, corresponds 

 with the activity of the organs which supply it. Cows which 

 give most milk a day, also give it longest; and hence, if no 



