while some were comparatively light and nimble, others were com
paratively large and clumsy. Now, introducing upon the scene the
common ancestor of the lion and the leopard—by immigration either
from Asia or from some other adjacent territory now submerged—let
us note some probable features of the complex result. First as regards
the attacked ruminants, it is likely that in course of time the lightest
and swiftest individuals, habitually taking refuge in flight, would have
greatly increased both in fleetness and in timidity ; the largest and
most clumsy of the species, unable to save themselves by fleeing, would
often be forced to stand and fight for their lives, and would thus
ultimately have gained in size, strength and courage; while those who
were neither nimble enough to get out of the way nor strong enough
to fight successfully, would have all been killed off. And thus after a
while, by perpetual destruction of the means and preservation of the
extremes, we should get two kinds of ruminant, as different from one
another as the antelope, which escapes by his fleetness and cautious
timidity, and the buffalo, which boldly withstands the lion and not
unfrequently conquers or repulses him.”—{Cosmic Philosophy, vol. ii.,
p. 18.)
Mr. Fiske here makes three assumptions, (i) He pre
supposes the pre-existence of two nascent varieties in a
given species—some being comparatively light and nimble,
others comparatively large and clumsy. (2) He assumes
that the light variety would seek safety in flight, and that
the heavy variety would try to escape destruction by
standing still and fighting for their lives. (3) He takes
for granted that the fleetest and most timid of the one
section and the strongest and most brave of the other
section would be saved, and so a bifurcation of species
would take place. But how, I would ask, could the initial
difference have arisen in a species which had the same
habits? There would be no light and nimble specimens
of a race which was never pursued ; there would be no
heavy and clumsy specimens in a species which had con
stantly to run for its life. Why should a herd of deer
which act for the common good and stick together take
to two modes of saving themselves ? And there is the
second difficulty, already dwelt upon, that the co-operation