Origin of Yield Mark. 45 



To facil'itate explanation, a number of special illustra- 

 tions become necessary, most of which, that are connected 

 with this chapter, are grouped in Plate IV. Figure 2 is a 

 section of the hind quarter, with half of the udder of a cow 

 of small yield, and small-sized udder to correspond. The 

 yield being small, the hair on the twist grows downward, 

 as on the outside of the thighs, and the skin is closely at- 

 tached to the flesh. 



On the contrary, the hair on the back of the udder in 

 the section, figure i, turns upward, and the skin, or upper 

 part of the udder sack, is only loosely attached to the flesh. 

 In this figure — which may serve as a section through the 

 central part of one side of the udder, about in the natural 

 way — the udder is large ; indeed, it is four or five sizes 

 larger than the small or natural-sized udder, as shown in the 

 small size, figure i, in same cut, and in figure 2. As appears 

 from the great disparity in size, the large udder may be 

 capable of containing and yielding four gallons at the usual 

 milking time, while the small-sized udder scarcely yields 

 as many pints. The question is not yield, however, but 

 the cause of the "Yield Mark," and, as the hair grows 

 downward, and the skin clings closely to the flesh, in the 

 small-uddered cow, while the upper part of the bag is sep- 

 arate from the flesh, and the hair grows upwai-d, on the sep- 

 arated skin where there is evidently a large "Yield Mark" 

 corresponding with the size of the udder, and the quantity 

 of yield, which figure i may serve to indicate, approxi- 

 mately. 



It seems best to trace this peculiar figure of reveised hair 

 to its origin step by step, so as to comprehend it clearly 

 and fully. If the outside part only, of the hair on the twist 

 of larffe yielding cows were alone bent upward, there 

 would be a sharp bend at the surface of the skin, as seen 

 in Fig. 4. But the reversed hair is not so bent, but 

 grows, all in the same lineal direction ; the root ends, or 



