226 Life-histories of Northern Animals 



Hole, was a male under six months old, so that all the propor- 

 tions, and indeed the character, were much less developed than 

 in the adult. (Fig. 99.) 



The fresh skin was laid flat on a board, and then the 

 pattern and mechanism of the rump-natch were clearly seen. 

 The hairs at the upper part of the patch (A) were about 4 inches 

 long, grading to the centre (B), and the lower parts, where they 

 were under 2 inches long, all snowy white and normally lying 

 down flat, pointing toward the rear. At 

 the point (B), among the roots of the hair, 

 was a gland secreting a fluid having a 

 strong musky smell. On the under side of 

 the skin was a broad sheet of muscular 

 fibres, which were thickest around B; they 

 have power to change the direction of the 

 hair, so that all below B stands out, and 

 Fig. g^skin of crupper-discs. hII above is dircctcd forward. 

 At AA the hair was about four inches It sccms, thcrcforc, that as soott as an 



long ; at and below BB less than ' ' 



two inchei ; at CCC. between the A ^ 1 >. 



two patches, it was one-quarter Autelopc sccs some straugc pcrsotts or 



inch long. * ox 



threatening object, this muscle acts, and 

 the rump-patch is instantly changed into a great double disk 

 of white that shines afar like a patch of snow. Further, in the 

 middle of each disk is exposed a brown spot (the musk-gland), 

 from which a quantity of the musk odour is set free, and its 

 message is read by those who have noses to read. 



Of all animals man has the poorest nose. He has virtually 

 lost the sense of smell, while, among the animals next in the 

 scale, scent is their best faculty. Yet even man can distinguish 

 this danger-scent for 20 or 30 yards down the wind, and there 

 is every reason to believe that another Antelope can detect it 

 a mile away. 



Observations on captive animals have thus afforded the 

 key to those made on the Plains. I know now that the flashing 

 flecks seen on the Yellowstone uplands were the interchanging 

 signals of the two bands, the smaller of which, on getting the 

 musky message, "Friends," had laid aside their fears and 

 joined their kindred. This, it will be seen, is simply a helio- 



