706 THE NATIONAL ZOO AT WASHINGTON. 



and raised his head to gaze in the direction where the first was gazing. 

 At the same time 1 noticed on the wind a peculiar musky smell — a 

 smell that certainly came from the antelope. 



Some time later the opportunity came to make a careful dissection 

 of the antelope's rump patch, and the keystone to the arch of facts was 

 supplied. My specimen, taken in Jacksons Hole, was a male under 

 six months old, so that all the proportions, and indeed the character, 

 are much less developed than in the adult. (Plate III.) 



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

 mechanism of the rump patch were clearly seen. The hairs at the 

 upper part of the patch (A) were 3f inches long, grading to the 

 center (B) and lower parts, where they were only If 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 

 strong musk. On the under side of the skin was a broad sheet of mus- 

 cular fibers, which were thickest around j9; they have power to change 

 the direction of the hair, so that all below B stands out, and all above 

 is directed forward. As soon, therefore, as an antelope sees some 

 strange or thrilling object, this muscle acts, and the rump patch is 

 changed in a flash into a great double disk or twin chrysanthemum of 

 white, that shines afar like a patch of snow; but in the middle of each 

 bloom a dark brown spot, the musk gland, is exposed, a great quantity 

 of the odor is set free, and the message is read by all those that have 

 noses to read. 



Of all animals man has the poorest nose; he has virtually lost the 

 sense of smell, while among the next animals in the scale scent is their 

 best faculty; yet even man can distinguish this danger scent for many 

 yards down wind, and there is no reason to doubt that another ante- 

 lope can detect it a mile away. 



Thus the observations on the captive animals living under normal 

 conditions prove the key to those made on the plains, and I know now 

 that the changing flecks in the Yellowstone uplands were made by this 

 antelope heliograph while the two bands signaled each other, and the 

 smaller band, on getting the musky message, "Friends," laid aside all 

 precaution and fearlessly joined their relations. 



This animal has five different sets of glands about it, each exuding a 

 different kind of musk for use in its daily life, as a moans of getting 

 and giving intelligence to its kind. These are situated one on each 

 foot between the toes, one on each angle of the jaw, one on the back 

 of each hock, one on the middle of each disk on the rump, and one at 

 the base of the tail. 



Those on the jaw seem related to the sexual system, as they are 

 largest in the buck; those on the rump, as seen, have a place in their 

 heliograph ic code; and the purpose of the others, though not yet fully 

 worked out, is almost certainly to serve in conveying the news. To 



