GROWTH OF HORNS. PROBOSCIS. 



103 



fate of all bones deprived of their soft surrounding parts and 

 remaining exposed to the air ; that which takes place as a result 

 of injury in the human body, here occurs in consequence of the 

 natural changes which have been just related. The bone is 

 affected with the disease termed Necrosis^ dies, and finally 

 detaches itself from the head, and falls off. The animal then 

 remains unarmed ; but after a short time (generally 24 hours), 

 a thin pellicle covers the wound created by the fall of the horn, 

 and a fresh bony prominence soon rises up in the place of the 

 old one. In general the new horn acquires much greater size 

 than that which it succeeded. The number of its branches is 

 also usually much more considerable ; but it does not last longer, 

 and it passes through the same changes as the first. It is 



generally in spring that these curious 

 phenomena take place ; and the re- 

 newal of these horns occurs nearly 

 every year. The male alone usually 

 has the head adorned in this manner. 

 One remarkable species, the Rein- 

 deer, forms, however, an exception 

 to this rule ; the female having 

 horns as well as the male. 



84. A curious anomaly, which is 

 met with in the conformation of the 

 head in certain Mammalia, depends 

 on an excessive development of the 

 nose, which is prolonged so as to 

 form a movable and prehensile 

 trunk. Such is, in fact, the nature 

 of the organ which gives so peculiar 

 an appearance to the Elephant, and 

 to which it owes its great address. 

 The trunk of these animals is a double tube, which is continuous 

 above with the cavity of the nose, and which is lined internally 

 with a nbro-tendinous membrane ; around this are fixed some 

 thousands of small muscles, variously twisted and arranged, so 

 as to lengthen it, to shorten it, and to bend it in all directions. 



FIG. 56 TRUNK OF AN ASIATIC 

 ELEPHANT. 



