OW few of the beauties, whose delicate ears, heaving bosoms, and supple wrists I am made to adorn, are acquainted with the faintest outline of my history and experience! I will leave it to my hearers to say whether my story is not worth listening to.

The period when I was born, and in whose rocks I am most commonly found, is that known to geologists by the name of the Lias. In the lignite portion of its strata, among the " Alum Shales," I occur in my natural state as lumps and nodules. When purest, I am deemed most valuable, on account of my use in the manufacture of the well-known jet ornaments. I am purely of vegetable origin-as

much so as coal itself-although I am usually considered a species of "black amber." Like the yellow variety which goes by that name, I am electric when briskly rubbed. As a fossil pitch or gum, I am related to the peculiar coniferous flora which grew so abundantly, although in comparatively few species, during the Liassic epoch. The chief features of these vegetable forms I shall presently endeavour to describe to the best of my recollection.

First, let me say a word as to the rock formation in which I am found. Why it is called the "Lias" few wise men know, so that I may be excused, seeing this name was given to it so many centuries after my birth. It is usually regarded as a corruption of the word "layers," and I think this is very probable, as the general appearance of the strata is such as to cause such a name to be given to them, par parenthese. Thin bands of dark limestone alternate with equally thin bands of dark shale, like so many sandwiches; this "ribbon-like" arrangement is very persistent, at least in England, and from it may have come the name of " Lias," or "Layers." The modern science of geology includes in its technical list many names which had a humble origin among quarrymen and miners. However that may be, I well remember the alternate stages of quiet and disturbance which affected the sea near where I was born. Sometimes its waters would remain calm and clear for years, during which colonies of shellfish or corals would grow over its bottom, and their

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accumulated remains form a bed of limestone. then the waters were thick and turbid with mud, which gradually settled to the bottom, lying on the top of the shell bed, and now appearing as a layer of shale. In fact, the alternation I have spoken of is itself a proof of the physical conditions which affected the Liassic sea. The thickness of the various strata is nothing like so great as that of the older formations, although the fossil remains are far more numerous, both in species and individuals. In the struggle for life," which had been perpetually going on since the first appearance of life in the Laurentian epoch, many new forms had been developed. The total thickness of the Lias is only about eleven or twelve hundred feet, and this is usually separated into three divisions, termed respectively the Upper, Middle, and Lower. The upper portion consists chiefly of clays, whilst the middle is composed of "marlstone," crowded with fossils. This part is remarkable for its containing iron-ore in such abundance as to be worked for that valuable metal in some localities. The Lower Lias is that most characterized by partings of shale and limestone, already mentioned, and is by far the thickest member of the group.

The dry land of this period was broken into a series of undulations, as it is at present, although the mountains were not so high as they are now. The uplands were thickly covered with woods and forests of Araucarian pines and thickets of fern;

Fig. 54.

whilst the lowlands were green with densely-packed cycads, plants now confined to tropical regions. About one hundred species of Lias plants are known to science, but not one has yet been met with which belonged to the class of which the oak, ash, or nettle are familiar examples. Indeed, this group was not introduced until the Cretaceous epoch, which followed the Liassic, after the lapse of enormous periods of time. The ferns were remarkable for having reticulated veins traversing their fronds. In the damper places, and by the riversides, there grew miniature forests of equisetites, nearly allied to existing species. This was almost the only "English" feature about the Liassic landscape. The trees grew in many places on the lowlands by the sea, and the dark mud was often charged with the bituminous or resin lumps, which, under the name of "jet," now compose my personal substance. Amid this somewhat monotonous vegetation there lived several

species of miniature marsupials-the only warmblooded creatures then in existence-which found

the chief means of their subsistence in the hosts of insects that peopled grove and plain. Land reptiles, also, were not absent, both as crocodiles, tree-lizards, and flying-lizards.

This was, indeed, "the Age of Reptiles." Reptilian life was then modified to the various functions now fulfilled by a higher class-the Mammalia. In the air, on the land, in the water, one met with reptilian adaptations at every step. The places now filled by the whales and seals were then occupied by the Ichthyosaurus and the Plesiosaurus. The great land reptiles (Deinosauria), which became so abundant during the later I may say the continuing "Oolite" period-stood in the room of modern carnivora and herbivora. Instead of bats and birds winging their way through the air, there were groups of Pterodactyles, some of them larger than the greatest bird now living. And, just And, just as there is a mechanical and anatomical arrangement now characterizing the specialized mammalia, and thus fitting them for their various functions and places, so during the "Age of Reptiles" the relatively lower forms were built on the same plan. The modification which converts the limbs of a whale into flappers, also converted those of the Ichthyosaurus into paddles; the adaptation which provides a fulcrum for the muscles of a bird by fusing several bones together, we find applied to the flying-lizards of the Lias period. So wonderfully simple is the great plan on which the Creator has chosen