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