t. I do not bring this forward as any evidence that these
animals were allied to Kangaroos, since I believe that nothing is more
injurious in science than assumptions which do not rest on a broad basis
of facts; but I wish only to show that these tracks recall other animals
besides Birds, with which they have been universally associated. And
seeing, as we do, that so many of the early types prophesy future forms,
it seems not improbable that they may have belonged to animals which
combined with reptilian characters some birdlike features, and also some
features of the earliest and lowest group of Mammalia, the Marsupials.
To sum up my opinion respecting these footmarks, I believe that they
were made by animals of a prophetic type, belonging to the class of
Reptiles, and exhibiting many synthetic characters.

The more closely we study past creations, the more impressive and
significant do the synthetic types, presenting features of the higher
classes under the guise of the lower ones, become. They hold the promise
of the future. As the opening overture of an opera contains all the
musical elements to be therein developed, so this living prelude of the
Creative work comprises all the organic elements to be successively
developed in the course of time. When Cuvier first saw the teeth of a
Wealden Reptile, he pronounced them to be those of a Rhinoceros, so
mammalian were they in their character. So, when Sommering first saw the
remains of a Jurassic Pterodactyl, he pronounced them to be those of a
Bird. These mistakes were not due to a superficial judgment in men who
knew Nature so well, but to this prophetic character in the early types
themselves, in which features were united never known to exist together
in our days.

* * * * *

The Jurassic epoch, next in succession, was a very important one in the
history of Europe. It completed the junction of several of the larger
islands, filling the channel between the central plateau of France and
the Belgian island, as well as that between the former and the island of
Bretagne, so that France was now a sort of crescent of land holding a
Jurassic sea in its centre, Bretagne and Belgium forming the two horns.
This Jurassic basin or inland sea united England and France, and it may
not be amiss to say a word here of its subsequent transformations.
During the long succession of Jurassic periods, the deposits of that
epoch, chiefly limestone and clays,