eclared that, "on the evidence of paleontology, the
evolution of many existing forms of animal life from their predecessors
is no longer an hypothesis, but an historical fact." In 1881 he
asserted that the evidence gathered in the previous decade had been so
unequivocal that, had the transmutation hypothesis not existed, "the
paleontologist would have had to invent it."

Since then the delvers after fossils have piled proof on proof in
bewildering profusion. The fossil-beds in the "bad lands" of western
America seem inexhaustible. And in the Connecticut River Valley near
relatives of the great reptiles which Professor Marsh and others
have found in such profusion in the West left their tracks on the
mud-flats--since turned to sandstone; and a few skeletons also have been
found. The bodies of a race of great reptiles that were the lords of
creation of their day have been dissipated to their elements, while the
chance indentations of their feet as they raced along the shores, mere
footprints on the sands, have been preserved among the most imperishable
of the memory-tablets of the world.

Of the other vertebrate fossils that have been found in the eastern
portions of America, among the most abundant and interesting are the
skeletons of mastodons. Of these one of the largest and most complete is
that which was unearthed in the bed of a drained lake near Newburg, New
York, in 1845. This specimen was larger than the existing elephants,
and had tusks eleven feet in length. It was mounted and described by Dr.
John C. Warren, of Boston, and has been famous for half a century as the
"Warren mastodon."

But to the student of racial development as recorded by the fossils all
these sporadic finds have but incidental interest as compared with the
rich Western fossil-beds to which we have already referred. From records
here unearthed, the racial evolution of many mammals has in the past few
years been made out in greater or less detail. Professor Cope has traced
the ancestry of the camels (which, like the rhinoceroses, hippopotami,
and sundry other forms now spoken of as "Old World," seem to have had
their origin here) with much completeness.

A lemuroid form of mammal, believed to be of the type from which man
has descended, has also been found in these beds. It is thought that the
descendants of this creature, and of the other "Old-World" forms
above referred to, found their way to Asia, probably, as suggested by
Professor Mars