t. These diagrams of the plesiosaurus,
the ichthyosaurus, the pterodactyle, give you a notion of some of these
extinct reptiles. And here is a cast of the pterodactyle and bones of
the ichthyosaurus and the plesiosaurus, just as fresh as if it had been
recently dug up in a churchyard. Thus, in the reptile class, there are
no less than half of the orders which are absolutely extinct. If we turn
to the 'Amphibia', there was one extinct order, the Labyrinthodonts,
typified by the large salamander-like beast shown in this diagram.

No order of fishes is known to be extinct. Every fish that we find in
the strata--to which I have been referring--can be identified and placed
in one of the orders which exist at the present day. There is not known
to be a single ordinal form of insect extinct. There are only two orders
extinct among the 'Crustacea'. There is not known to be an extinct order
of these creatures, the parasitic and other worms; but there are
two, not to say three, absolutely extinct orders of this class, the
'Echinodermata'; out of all the orders of the 'Coelenterata' and
'Protozoa' only one, the Rugose Corals.

So that, you see, out of somewhere about 120 orders of animals, taking
them altogether, you will not, at the outside estimate, find above ten
or a dozen extinct. Summing up all the orders of animals which have left
remains behind them, you will not find above ten or a dozen which cannot
be arranged with those of the present day; that is to say, that the
difference does not amount to much more than ten per cent.: and the
proportion of extinct orders of plants is still smaller. I think that
that is a very astounding, a most astonishing fact, seeing the enormous
epochs of time which have elapsed during the constitution of the surface
of the earth as it at present exists; it is, indeed, a most astounding
thing that the proportion of extinct ordinal types should be so
exceedingly small.

But now, there is another point of view in which we must look at this
past creation. Suppose that we were to sink a vertical pit through the
floor beneath us, and that I could succeed in making a section right
through in the direction of New Zealand, I should find in each of the
different beds through which I passed the remains of animals which I
should find in that stratum and not in the others. First, I should come
upon beds of gravel or drift containing the bones of large animals, such
as the elephant, rhinoceros, and cave t