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THE AMERICAN NATURALIST [Vol. XLYIK 



which both shoulder patches are present, though small. 

 In Figs. 41 and 42 the shoulder areas are wanting. A 

 very common mark in cows is a white belt just back of 

 the foreleg. This is due to the development of a primary 

 break between shoulder patches and side patches, a con- 

 dition which is nearly realized in Figs. 33 and 38. It is 

 probable that this marking has been more or less fixed 

 through selection in breeding, and this has been the more 

 readily accomplished, since this break occurs in a place 

 which is one of the first in cows to cease pigment 

 production. 



The side patch is large and covers the entire lateral 

 region of the body from the scapula to the hips, and on 

 to the front edge of the hind limb. When only slightly 

 reduced, it appears as a blanket-shaped area across the 

 back as in Fig. 38, where it has not wholly broken away 

 from the shoulder and rump patches, or as in Fig. 33, 

 where it has become nearly separated. In its further 

 reduction this dorsal blanket shows a peculiar manner of 

 breaking up into more or less transverse stripes directed 

 sliirhlly backward. The beginnings of these secondary 

 breaks appear in Fig. 39 in which are seen on each side 

 posteriorly two deep indentations at the edge of the 

 patch, whose points if extended would meet the white 

 pigmentless islands already present within the patch. 

 In Fig. 34 a similar series of indentations points to the 

 trisection of the side patch which is realized in Fig. 35. 

 Here is a characteristic which if developed might even- 

 tually result in the actual production of white stripes on 

 the body, such as are found, for example, in certain ante- 

 lopes as the bongo and the kudu. The tendency of the 

 side patch to divide into three, as in these diagrams, is 

 rather marked in cows, and even with further reduction 

 the three centers persist fairly well. The first of these 

 secondary centers is just back of the shoulder patch, the 

 second about over the last ribs, and the third over the 

 lumbar region. In Fig. 40 the first two are present on the 

 left side, with a small spot between, which has become 



