536 
THE LIVING WORLD, 
was still soft as the tusk is at the base, and which must subsequently 
have been carried along as the new ivory below pushed along the older ivory 
above. The elephant, like man, has milk-teeth, which in due course of time 
drop out and are succeeded by the second and permanent teeth. These teeth 
are peculiar, inasmuch as each one has three different structures. On the out¬ 
side the tooth is constituted for crushing, the next layer is adapted to tearing, 
and the last layer for grinding. Perhaps, as an illustration of the inter-depen¬ 
dence of all terrestrial life, it may be worth while to mention that the invention 
of celluloid, and the discovery of vegetable ivory, has, by furnishing a substi¬ 
tute for ivory, done much to postpone the time when the elephant will be an 
ELEPHANTS IN SERVICE. 
extinct animal. Elephants have been known to have three tusks, but these 
were mere lusus natures. 
Indian elephants when domesticated are made to earn their living, not 
simply as companions to the hunter, beasts of burden on a journey, or as ele¬ 
ments of a triumphal procession of royalty. By the British they have been 
made to act as animated gun-carriages, the howitzers being securely strapped 
to their backs and fired, while in that position. By the natives they are used 
m logging ” and in piling timber, and their great strength and patient intelli¬ 
gence render them the most useful, industrious, well-behaved and uncomplaining 
of lumbermen. & 
The natives transport the ivory either in the shape of long, heavy strips 
or cut up into squares and regular figures, and we present an illustration of 
