100 HEAL EXTENT OP THE MIRROR. 



in the midst of the mirror, Figs. 45, 46, and 47, or form 

 indentations on its edges, as in Figs. 42, 44, 45, 46, 

 and 48. 



These indentations, concealed in part by the folds of 

 the skin, are sometimes seen with difficulty ; but it is 

 important to take them into account, since in a great 

 many cows they materially lessen the size of the mir- 

 ror. We often find cows whose milk-mirror at first' 

 sight appears very large, but which are only medium 

 milkers; and it will usually be found that lateral indent- 

 ations greatly diminish the surface of up-growing hair. 

 Many errors are committed in estimating the value of 

 such cows, from a want of attention to the real extent 

 of the milk-mirror. 



All the interruptions in the surface of the mirror 

 indicate a diminution of the quantity of milk, with the 

 exception, however, of small oval or elliptical plates 

 which are found in the mirror, on the back part of the 

 udders of the best cows, as in Figs. 29, 30, 32, 34, 35, 

 36, and 40. These ovals have a peculiar tint, which 

 is occasioned by the downward direction of the hair 

 which forms them. In the best cows these ovals exist 

 with the lower mirrors very well developed, as in Figs. 

 29, 30, and 32. 



In fine, we should state that in order to determine 

 the extent and significance of a mirror it is necessary 

 to consider the state of the perineum as to fat, and of 

 the fulness of the udder. In a fat cow, with an in- 

 flated udder, the mirror would appear larger than it 

 really is; whilst in a lean cow, with a loose and wrinkled 

 udder, it appears smaller. Fat will cover faults, a fact 

 to be kept in mind in selecting a cow. 



In bulls, Fig. 51, the mirrors present the same pecu- 

 liarities as in cows ; but they are less varied in their 

 form, and especially much less in size. This will easily 



