longer find the lion standing alone, but with
the tiger on a par with him if not above him; but at the same time we
fall easy victims to the temptation to confound the tiger with "the many
other animals which are also called tigers." A surface stream has swept
the members of the cat family in different directions, but a stealthy
undercurrent has seized them from beneath, and they are now happily
reunited.

_Animals of the Old and New World--Changed Geographical Distribution._

Writing upon the animals of the old world,[101] and referring to the
humps of the camel and the bison, Buffon shows that very considerable
modification may be effected in some animals within even a few
generations, but he attributes the effect produced to the direct
influence of climate. Buffon concludes his sketch of the animals of the
new world by pointing out that the larger animals of the African torrid
zone have been hindered by sea and desert from finding their way to
America, and by claiming to be the first "even to have suspected" that
there was not a single denizen of the torrid zone of one continent which
was common also to the other.[102]

The animals common to both continents are those which can stand the cold
and which are generally suited for a temperate climate. These, Buffon
believes, to have travelled either over some land still unknown, or
"more probably," over territory which has long since been submerged. The
species of the old and new world are never without some well-marked
difference, which however should not be held sufficient for us to refuse
to admit their practical identity. But he maintains, I imagine wilfully,
that there is a tendency in all the mammalia to become smaller on being
transported to the new world, and refers the fact to the quality of the
earth, the condition of the climate, the degrees of heat and humidity,
to the height of mountains, amounts of running or stagnant waters,
extent of forest, and above all to the brutal condition of nature in a
new country, which he evidently regards with true aristocratic
abhorrence.[103]

Then follows a passage which I had better perhaps give in full:--

The mammoth "was certainly the greatest and strongest of all quadrupeds;
but it has disappeared; and if so, how many smaller, feebler, and less
remarkable species must have also perished without leaving us any traces
or even hints of their having existed? How many other species have
changed their nature, that is to