1

missing links," and those who make use of it little know that all the fossils are, more or less, of this nature, and fill up gaps in the natural history classification. Some of the reptiles of which I am speaking walked on two legs, like great Cochin China fowl, and with their hind quarters much more strongly developed than their fore limbs. In this respect they resembled, amongst the reptilia, the position of the kangaroo, which, as everybody knows,

Megalosaurus-a great terrestrial reptile.

generally uses only his huge hind legs, his fore limbs being much smaller and weaker. One of these land reptiles, named Compsognathus, whose remains have been found in the Stonesfield slate, and which was only about two or three feet in length, is the nearest approach, in its general structure, to birds of any yet made known. As you are aware, nearly all reptiles are egg-bearing in their habits, and the fossil eggs of

the Oolitic reptiles have been met with, showing that, so long ago as the Oolitic age, this class had the same habits as their diminutive representatives of the present day. But what is very remarkable is, that whilst the reptiles of this period had bird-like characters, the only birds known had reptilian pecu

Archeopteryx (restored), from the Oolitic Limestone of Solenhofen.

liarities! No doubt you are aware that these two great groups of animals, birds and reptiles, follow each other in ordinary classification. They do so in order of time, the reptiles first in their lowest grade as Amphibia (Labyrinthodonts), which gradually rise

to a higher standard in the Ichthyosaurus, until they assume features which, as I above remarked, now belong wholly to birds. Singularly enough, the true birds follow soon after, and the first specimen you meet with shows, in the structure of its tailbones, &c., that it had borrowed some of the anatomical peculiarities of the reptiles! This bird had a long attenuated tail, like that of a lizard, with feathers bifurcating from each side down to the end. This strange bird is now known as the Archæopteryx, and its bones, and even feathers, have been found beautifully preserved in the Solenhofen stone. Here you have, at any rate, a meetingground on which two of the great divisions of the animal kingdom exhibit their mutual descent. It is a suggestive fact for those of my hearers who are sceptical about "missing links!"

The ages which have passed away since these things occurred are bewildering to those who are anxious to know, in so many years, how old the world is, as if that fact would add anything material to their real knowledge. At the time of which I am speaking, the area occupied by the Himalaya Mountains was a deep sea-bottom: that great mass has been slowly elevated to its present great height since the era of my birth. The Jura Alps were in the same condition, and have undergone similar elevation. One generation of animals and plants after another has passed away from the earth, having been slowly pushed out of existence by newly-formed

species, better fitted to the alterations effected through the changes in physical geography. The whole of the Oolitic strata of soft sands, oozy lime, and dark mud, as well as the beds of loose freshwater shells, have undergone chemical action and change, and been transformed into sandstones, limestones, shales, and Purbeck marbles. Our family has been in past times, and is now, a favourite with man in his endeavour to express his religious convictions and aesthetical feelings. We form the stonework of his grand churches and cathedrals, and I myself have the honoured position of forming part of his altar, his christening-font, or his graveslab! The tread of many generations of men has not effaced my lacustrine origin. Dynasties and religions have passed away, and been replaced by others breathing a more Christian and liberal spirit, just as the Oolitic animals were replaced by those of a higher organization; but I still form part of these grand structures, silently testifying to the endurability of nature over art, and yet myself a testimony that Nature herself is full of changes, and restlessly advances to a more perfect condition!

CHAPTER X.

THE STORY OF A PIECE OF CHALK.

"There rolls the deep where grew the tree,
Oh earth, what changes hast thou seen!
There, where the long street roars, hath been
The stillness of the central sea."

TENNYSON.

T is so long ago that I can hardly remember it. My first recollections are of a white, muddy sediment, hundreds of feet in thickness, stretching along the bottom of a very deep

Fig. 83.

Fig. 84.

Fig. 85.

Fig. 86.

Nodosaria limbata, Chalk, Charing.

sea.

FORAMINIFERA FROM THE ENGLISH CHALK.

Of this oozy bed I formed an inconsiderable part. The depth of sea-water which pressed down