XXI 



HORNS 267 



Europe, need not cletaiu ii.s long, for ileer are not found 

 in Africa. Structurallj^, they are outgrowths from the 

 frontal Ixine, and consist entirely of lione. During their 

 growth, antlers are covered with skin beset with hairs 

 and sebaceous glands ; the skin covering an antler is 

 continu(jus with that on the deer's head ; so long as its 

 antlers are covered with skin, the stag is said to be " in 

 velvet." 



Antlers in this condition are sensitive to knocks and 

 blows, Init when full-grown the velvet peels off and the 

 Ijare l)one remains. Peeled antlers are insensitive, and 

 the bucks use them to fight rivals. In fighting, the 

 antlers are used with such violence that a tine or 

 occasionally the beam is brokeir. At the end of the 

 rutting season the antlers fall off, and are annually 

 renewed. In the majority of deer it is the buck alone 

 which is ornamented with horns. 



The rapidity with wdiich antlers grow is astonishing. 

 The Wapiti {Cervus canadensis) has antlers weighing 

 thirty-two or more pounds, yet these huge masses of 

 bone are reproduced in five months. In the Zoological 

 Gardens during the growth of the antlers it is usual to 

 doul)le the wapiti's allowance of food. 



Horns of the second kind are characteristic of the 

 Family Boindce, which comprises oxen, sheep, goats, 

 and antelopes. These animals are sometimes called the 

 sheath-horned ruminants, because their horns consist of 

 a core of bone connected with the frontal bone, covered 

 with a sheath of hard material derived from the super- 

 ficial (epithelial) layer of the skin. This horny sheath 

 corresponds to the velvet of the deer's antler, but it is 

 insensitive. Mammals possessing such horns are some- 

 times spoken of as the Cavicornia or Hollow-horned. 

 These horns differ from antlers in the fact that they 

 are never shed and never branch. 



The horns of antelopes present great variety in shape 

 and size. They are also useful to the zoologist for the 

 purposes of classification. 



