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the remarkable Deinocerata ("terrible-horned" mammals). They sometimes
measured thirteen feet in length, but had little use for brain in the
conditions in which they were developed. The brain of the Deinoceras was
only one-eighth the size of the brain of a rhinoceros of the same
bulk; and the rhinoceros is a poor-brained representative of the modern
mammals. To meet the growing perils of their race they seem to have
developed three pairs of horns on their long, flat skulls, as we find
on them three pairs of protuberances. A late specimen of the group,
Tinoceras, had a head four feet in length, armed with these six horns,
and its canine teeth were developed into tusks sometimes seven or
eight inches in length. They suggest a race of powerful but clumsy and
grotesque monsters, making a last stand, and developing such means of
protection as their inelastic nature permitted. But the horns seem to
have proved a futile protection against the advancing carnivores, and
the race was extinguished. The horns may, of course, have been mainly
developed by, or for, the mutual butting of the males.

The extinction of these races will remind many readers of a theory on
which it is advisable to say a word. It will be remembered that the
last of the Deinosaurs and the Ammonites also exhibited some remarkable
developments in their last days. These facts have suggested to some
writers the idea that expiring races pass through a death-agony, and
seem to die a natural death of old age like individuals. The Trilobites
are quoted as another instance; and some ingenious writers add the
supposed eccentricities of the Roman Empire in its senile decay and a
number of other equally unsubstantial illustrations.

There is not the least ground for this fantastic speculation. The
destruction of these "doomed races" is as clearly traceable to external
causes as is the destruction of the Roman Empire; nor, in fact, did the
Roman Empire develop any such eccentricities as are imagined in this
superficial theory. What seem to our eye the "eccentricities" and
"convulsions" of the Ceratopsia and Deinocerata are much more likely
to be defensive developments against a growing peril, but they were
as futile against the new carnivores as were the assegais of the Zulus
against the European. On the other hand, the eccentricities of many
of the later Trilobites--the LATEST Trilobites, it may be noted,
were chaste and sober specimens of their race, like the last R