THE MASTODON =, 199 
in the theory of evolution, with elephants hav- 
ing an intermediate pattern of teeth. 
There is usually, or at least often, another 
point of difference between elephants and mas- 
todons, for many of the latter not only had 
tusks in the upper, but in the lower jaw, and 
these are never found in any of the true ele- 
phants. The lower tusks are longer and larger 
Fig. 38.— Tooth of Mastodon and of Mammoth. 
in the earlier species of mastodon than in 
those of more recent age and in the latest spe- 
cies, the common American mastodon, the lit- 
tle lower tusks were usually shed early in life. 
These afford some hints of the relationships of 
the mastodon; for in Europe are found re- 
mains of a huge beast well called Dinotheri- 
um, or terrible animal, which possessed lower 
tusks only, and these, instead of sticking out 
