IN THE LOWER ANIMALS, ETC. 313 



sively males; nearly all, however, are provided 

 with the stunted teeth called tushes, about ten or 

 twelve inches in length, and one or two in dia- 

 meter. The old naturalists maintain that the 

 elephant periodically sheds his tusks, ^lian says 

 he drops them once in ten years ; and Pliny repeats 

 the story, adding that, when dropped, the ele- 

 phants hide them under ground; whence Shaw 

 says, in his ' Zoology,' *' They are frequently found 

 in the woods, and exported from Africa;" and Sir 

 W. Jardine, in the 'Naturalist's Library,' says, 

 " The tusks are shed about the twelfth or thir- 

 teenth year." This is erroneous : after losing the- 

 first pair, or '^ milk tusks " (which drop in conse- 

 quence of the absorption of their roots, when the 

 animal is extremely young), the second pair 

 acquire their full size, and become the permanent 

 tusks, which are never shed. Elephant-tusks are 

 not unfrequently found in which balls of iron or 

 lead are imbedded in the solid ivory, a pheno- 

 menon which is thus explained : '' The ball pro- 

 bably has penetrated the thin parietes of the 

 socket, and the wall of the wide pulp cavity 

 forming the basal extremity of the tusk. If the 

 projectile force be then spent, the ball gravitates 

 to the opposite and lower side of the pulp cavity. 

 The presence of the foreign body exciting inflam- 

 mation of the pulp, an irregular course of calcifi- 

 cation ensues, which results in the deposition 

 around the ball of a certain thickness of osteo- 



