imagination of a poet,” they could not “for a moment bear the
examination of anyone who has dissected a hand, a viscus, or even a
feather.”
Having dismissed transformisme, Cuvier was left with a gaping hole. He
had no account of how new organisms could appear, nor any explanation
of how the world could have come to be populated by different groups of
animals at different times. This doesn’t seem to have bothered him. His
interest, after all, was not in the origin of species but in their demise.
THE very first time he spoke about the subject, Cuvier intimated that
he knew the driving force behind extinction, if not the exact mechanism.
In his lecture on “the species of elephants, both living and fossil,” he
proposed that the mastodon, the mammoth, and the Megatherium had all
been wiped out “by some kind of catastrophe.” Cuvier hesitated to
speculate about the precise nature of this calamity—“It is not for us to
involve ourselves in the vast field of conjectures that these questions
open up,” he said—but he seems to have believed at that point that one
disaster would have sufficed.
Later, as his list of extinct species grew, his position changed. There
had, he decided, been multiple cataclysms. “Life on earth has often been
disturbed by terrible events,” he wrote. “Living organisms without
number have been the victims of these catastrophes.”
Like his view of transformisme, Cuvier’s belief in cataclysm fit with—
indeed, could be said to follow from—his convictions about anatomy.
Since animals were functional units, ideally suited to their circumstances,
there was no reason why, in the ordinary course of events, they should
die out. Not even the most devastating events known to occur in the
contemporary world—volcanic eruptions, say, or forest fires—were
sufficient to explain extinction; confronted with such changes, organisms
simply moved on and survived. The changes that had caused extinctions
must therefore have been of a much greater magnitude—so great that
animals had been unable to cope with them. That such extreme events