98 GUENON EXPLAINED. 



as seen in the same figures, or by curved lines, as in Fig. 

 34. It sometimes rises scarcely a fourth part up the 

 perineum, as in Fig. 38 ; at others, it reaches or passes 

 beyond that part, forming a straight band, as in Figs. 

 35 and 43, or is folded into squares, as in Figs. 31 and 36, 

 or truncated, Fig. 38, or terminated by one or several 

 points, Figs. 32, 33, 41, 50. In some cows this band 

 extends as far as the base of the vulva, Figs. 40 and 

 48 ; in others, it embraces more or less of the lower 

 part of the vulva, Figs. 29, 30, 39, and 47. 



Milk-mirrors are sometimes symmetrical, as in Figs. 

 29, 30, 34, 35, 37, and 38 ; sometimes without sym- 

 metry, as in Figs. 42, 45, and 50. When there is a great 

 difference in the extent of the two halves, it almost 

 always happens that the teats on the side where the 

 mirror is best developed give, as we shall see, more 

 milk than those of the opposite side. We will remark 

 here that the left half of the mirror is almost always 

 the largest ; arid so, when the perinean part is folded 

 into a square, it is on this side of the body that it un- 

 folds, as in Figs. 31, 36, and 42. Of three thousand cows 

 in Denmark, M. Andersen found only a single one whose 

 escutcheon varied even a little from this rule. We have 

 observed the contrary only in a single case, and that 

 was on a bull. The perinean part of the mirror 

 formed a band of an inch to an inch and a half in 

 breadth, irregular, but situated, in great measure, on 

 the right side of the body. Stretching towards the 

 upper part of the perineum, it formed a kind of 

 square, with a small projecting point on the right, 

 Pig. 51. 



The mirrors having a value in proportion to tb*. 

 space they occupy, it is of great importance to at- 

 tend to all the rows of down-growing hairs, which 

 diminish its extent of surface, whether these tufts are 



