102 ANIMALS OF THE PAST 
one is broken midway between tip and base; | 
and that it was broken during life is evident 
from the fact that the stump is healed and — 
rounded over, while the size of the horns shows 
that their owner reached a ripe old age. 
For, unlike man and the higher vertebrates, 
reptiles and fishes do not have a maximum 
standard of size which is soon reached and 
rarely exceeded, but continue to grow — 
throughout life, so that the size of a turtle, a ~ 
crocodile, or a Dinosaur tells something of the i 
duration of its life. i 
Before quitting Triceratops let us glance for — 
a moment at its skeleton. Now among other — 
things a skeleton is the solution of a problem 
in mechanics, and in Triceratops the head so — 
dominates the rest of the structure that one— 
might almost imagine the skull was made first © 
and the body adjusted to it. The great head — 
seems made not only for offence and defence ; | 
the spreading frill serves for the attachment — 
of muscles to sustain the weight of the skull, | 
while the work of the muscles is made easier | 
by the fact that the frill reaches so far back | 
of the junction of head with neck as to largely 
