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THE AMERICAN NATURALIST [Vol. XLVIII 



patches is seen in Fig. 32, but, as commonly, the neck 

 patches seem fused in the midventral line. This shifting 

 of the neck centers ventrally is a rather remarkable 

 phenomenon which may have some relation to the manner 

 in which the head is held erect. For this reason it might 

 be expected also in antelopes, and is perhaps evidenced 

 in such a species as the oryx, in which there is a black 

 median line on the throat as though strongest pigment 

 production centered there rather than on the gray sides 

 of the neck. The median reduction of the shoulder 

 patches in horses is sometimes indicated by a white mane. 



The rump patches in the horse appear to be much as in 

 other mammals, restricted to the tail and posterior part 

 of the buttocks and the entire foot. In Fig. 30 the patch 

 is shown at nearly its full development, except that it has 

 failed to extend to the entire hind foot. In Fig. 27 it has 

 drawn away still farther but remains in contact with the 

 side patch at one place. In Fig. 29 it is further restricted 

 to the tail and posterior border of the haunches, while in 

 Fig. 32 it covers only the root of the tail and that member. 



The side patch is the largest of all and extends from 

 the shoulder to the fore part of the haunches and on to the 

 fore part of the hind leg nearly to the foot, as seen in Figs. 

 27 and 28, where it is still in contact with the rump patch, 

 or in Fig. 29 where it has become separated. In its fur- 

 ther reduction this patch may appear as a small spot 

 back of the ribs or, as often, a curious division takes 

 place, separating the patch into a dorsal area and a 

 lateral one. Occasionally this secondary break appears 

 in a horse which has most of its patches otherwise well 

 developed. In Fig. 31, the pigmented area of the tail, 

 buttocks and lumbar region consists of the conjoined rump 

 patch and a dorsal portion of the side patch, while the 

 ventral part of the side patch is present as the oval spot 

 at the groin. In Fig. 30 the latter spot only persists, but 

 in Fig. 32 the dorsal portion of the side patch alone is 

 present as a stripe along the entire back, except where it 

 breaks away posteriorly from the small rump patch. 



