by Grant Allen
The reptiles, again, are a class in which the biggest modern forms are simply nowhere beside the gigantic extinct species. First appearing on the earth at the very close of the vast primary periods — in the Permian age — they attained in secondary times the most colossal proportions, and have certainly never since been exceeded in size by any later forms of life in whatever direction. But one must remember that during the heyday of the great saurians, there were as yet no birds and no mammals. The place now filled in the ocean by the whales and grampuses, as well as the place now filled in the great continents by the elephants, the rhinoceroses, the hippopotami, and the other big quadrupeds, was then filled exclusively by huge reptiles, of the sort rendered familiar to us all by the restored effigies on the little island in the Crystal Palace grounds. Every dog has his day, and the reptiles had their day in the secondary period. The forms into which they developed were certainly every whit as large as any ever seen on the surface of this planet, but not, as I have already shown, appreciably larger than those of the biggest cetaceans known to science in our own time.
During the very period, however, when enaliosaurians and pterodactyls were playing such pranks before high heaven as might have made contemporary angels weep, if they took any notice of saurian morality, a small race of unobserved little prowlers was growing up in the dense shades of the neighbouring forests which was destined at last to oust the huge reptiles from their empire over earth, and to become in the fulness of time the exclusively dominant type of the whole planet. In the trias we get the first remains of mammalian life in the shape of tiny rat-like animals, marsupial in type, and closely related to the banded ant-eaters of New South Wales at the present day. Throughout the long lapse of the secondary ages, across the lias, the oolite, the wealden, and the chalk, we find the mammalian race slowly developing into opossums and kangaroos, such as still inhabit the isolated and antiquated continent of Australia. Gathering strength all the time for the coming contest, increasing constantly in size of brain and keenness of intelligence, the true mammals were able at last, towards the close of the secondary ages, to enter the lists boldly against the gigantic saurians. With the dawn of the tertiary period, the reign of the reptiles begins to wane, and the reign of the mammals to set in at last in real earnest. In place of the ichthyosaurs we get the huge cetaceans; in place of the deinosaurs we get the mammoth and the mastodon; in place of the dominant reptile groups we get the first precursors of man himself.
The history of the great birds has been somewhat more singular. Unlike the other main vertebrate classes, the birds (as if on purpose to contradict the proverb) seem never yet to have had their day. Unfortunately for them, or at least for their chance of producing colossal species, their evolution went on side by side, apparently, with that of the still more intelligent and more powerful mammals; so that, wherever the mammalian type had once firmly established itself, the birds were compelled to limit their aspirations to a very modest and humble standard. Terrestrial mammals, however, cannot cross the sea; so in isolated regions, such as New Zealand and Madagascar, the birds had things all their own way. In New Zealand, there are no indigenous quadrupeds at all; and there the huge moa attained to dimensions almost equalling those of the giraffe. In Madagascar, the mammalian life was small and of low grade, so the gigantic æpyornis became the very biggest of all known birds. At the same time, these big species acquired their immense size at the cost of the distinctive birdlike habit of flight. A flying moa is almost an impossible conception; even the ostriches compete practically with the zebras and antelopes rather than with the eagles, the condors, or the albatrosses. In like manner, when a pigeon found its way to Mauritius, it developed into the practically wingless dodo; while in the northern penguins, on their icy perches, the fore limbs have been gradually modified into swimming organs, exactly analogous to the flippers of the seal.
Are the great animals now passing away and leaving no representatives of their greatness to future ages? On land at least that is very probable. Man, diminutive man, who, if he walked on all fours, would be no bigger than a silly sheep, and who only partially disguises his native smallness by his acquired habit of walking erect on what ought to be his hind legs — man has upset the whole balanced economy of nature, and is everywhere expelling and exterminating before him the great herbivores, his predecessors. He needs for his corn and his bananas the fruitful plains which were once laid down in prairie or scrubwood. Hence it seems not unlikely that the elephant, the hippopotamus, the rhinoceros, and the buffalo must go. But we are still a long way off from that final consummation, even on dry land; while as for the water, it appears highly probable that there are as good fish still in the sea as ever came out of it. Whether man himself, now become the sole dominant animal of our poor old planet, will ever develop into Titanic proportions, seems far more problematical. The race is now no longer to the swift, nor the battle to the strong. Brain counts for more than muscle, and mind has gained the final victory over mere matter. Goliath of Gath has shrunk into insignificance before the Gatling gun; as in the fairy tales of old, it is cunning little Jack with his clever devices who wins the day against the heavy, clumsy, muddle-headed giants. Nowadays it is our ‘Minotaurs’ and ‘Warriors’ that are the real leviathans and behemoths of the great deep; our Krupps and Armstrongs are the fire-breathing krakens of the latter-day seas. Instead of developing individually into huge proportions, the human race tends rather to aggregate into vast empires, which compete with one another by means of huge armaments, and invent mitrailleuses and torpedos of incredible ferocity for their mutual destruction. The dragons of the prime that tare each other in their slime have yielded place to eighty-ton guns and armour-plated turret-ships. Those are the genuine lineal representatives on our modern seas of the secondary saurians. Let us hope that some coming geologist of the dim future, finding the fossil remains of the sunken ‘Captain,’ or the plated scales of the ‘Comte de Grasse,’ firmly embedded in the upheaved ooze of the existing Atlantic, may shake his head in solemn deprecation at the horrid sight, and thank heaven that such hideous carnivorous creatures no longer exist in his own day.
FOSSIL FOOD
There is something at first sight rather ridiculous in the idea of eating a fossil. To be sure, when the frozen mammoths of Siberia were first discovered, though they had been dead for at least 80,000 years (according to Dr. Croll’s minimum reckoning for the end of the great ice age), and might therefore naturally have begun to get a little musty, they had nevertheless been kept so fresh, like a sort of prehistoric Australian mutton, in their vast natural refrigerators, that the wolves and bears greedily devoured the precious relics for which the naturalists of Europe would have been ready gladly to pay the highest market price of best beefsteak. Those carnivorous vandals gnawed off the skin and flesh with the utmost appreciation, and left nothing but the tusks and bones to adorn the galleries of the new Natural History Museum at South Kensington. But then wolves and bears, especially in Siberia, are not exactly fastidious about the nature of their meat diet. Furthermore, some of the bones of extinct animals found beneath the stalagmitic floor of caves, in England and elsewhere, presumably of about the same age as the Siberian mammoths, still contain enough animal matter to produce a good strong stock for antediluvian broth, which has been scientifically described by a high authority as pre-Adamite jelly. The congress of naturalists at Tübingen a few years since had a smoking tureen of this cave-bone soup placed upon the dinner-table at their hotel one evening, and pronounced it with geological enthusiasm ‘scarcely inferior to prime ox-tail.’ But men of science, too, are accustomed to trying unsavoury experiments, which would go sadly against the grain with less philosophic and more squeamish palates. They think nothing of tasting a caterpillar that birds will not touch, in order to discover whether it owes its immunity from attack to some nauseous, bitter, or pungent flavouring; and they even advise you calmly to discriminate between two closely similar species of snails by trying which of them when chew
ed has a delicate soupçon of oniony aroma. So that naturalists in this matter, as the children say, don’t count: their universal thirst for knowledge will prompt them to drink anything, down even to consommé of quaternary cave-bear.
There is one form of fossil food, however, which appears constantly upon all our tables at breakfast, lunch, and dinner, every day, and which is so perfectly familiar to every one of us that we almost forget entirely its immensely remote geological origin. The salt in our salt-cellars is a fossil product, laid down ages ago in some primæval Dead Sea or Caspian, and derived in all probability (through the medium of the grocer) from the triassic rocks of Cheshire or Worcestershire. Since that thick bed of rock-salt was first precipitated upon the dry floor of some old evaporated inland sea, the greater part of the geological history known to the world at large has slowly unrolled itself through incalculable ages. The dragons of the prime have begun and finished their long (and Lord Tennyson says slimy) race. The fish-like saurians and flying pterodactyls of the secondary period have come into existence and gone out of it gracefully again. The whole family of birds has been developed and diversified into its modern variety of eagles and titmice. The beasts of the field have passed through sundry stages of mammoth and mastodon, of sabre-toothed lion and huge rhinoceros. Man himself has progressed gradually from the humble condition of a ‘hairy arboreal quadruped’ — these bad words are Mr. Darwin’s own — to the glorious elevation of an erect, two-handed creature, with a county suffrage question and an intelligent interest in the latest proceedings of the central divorce court. And after all those manifold changes, compared to which the entire period of English history, from the landing of Julius Cæsar to the appearance of this present volume (to take two important landmarks), is as one hour to a human lifetime, we quietly dig up the salt to-day from that dry lake bottom and proceed to eat it with the eggs laid by the hens this morning for this morning’s breakfast, just as though the one food-stuff were not a whit more ancient or more dignified in nature than the other. Why, mammoth steak is really quite modern and common-place by the side of the salt in the salt-cellar that we treat so cavalierly every day of our ephemeral existence.
The way salt got originally deposited in these great rock beds is very well illustrated for us by the way it is still being deposited in the evaporating waters of many inland seas. Every schoolboy knows of course (though some persons who are no longer schoolboys may just possibly have forgotten) that the Caspian is in reality only a little bit of the Mediterranean, which has been cut off from the main sea by the gradual elevation of the country between them. For many ages the intermediate soil has been quite literally rising in the world; but to this day a continuous chain of salt lakes and marshes runs between the Caspian and the Black Sea, and does its best to keep alive the memory of the time when they were both united in a single basin. All along this intervening tract, once sea but now dry land, banks of shells belonging to kinds still living in the Caspian and the Black Sea alike testify to the old line of water communication. One fine morning (date unknown) the intermediate belt began to rise up between them; the water was all pushed off into the Caspian, but the shells remained to tell the tale even unto this day.
Now, when a bit of the sea gets cut off in this way from the main ocean, evaporation of its waters generally takes place rather faster than the return supply of rain by rivers and lesser tributaries. In other words, the inland sea or salt lake begins slowly to dry up. This is now just happening in the Caspian, which is in fact a big pool in course of being slowly evaporated. By-and-by a point is reached when the water can no longer hold in solution the amount of salts of various sorts that it originally contained. In the technical language of chemists and physicists it begins to get supersaturated. Then the salts are thrown down as a sediment at the bottom of the sea or lake, exactly as crust formed on the bottom of a kettle. Gypsum is the first material to be so thrown down, because it is less soluble than common salt, and therefore sooner got rid of. It forms a thick bottom layer in the bed of all evaporating inland seas; and as plaster of Paris it not only gives rise finally to artistic monstrosities hawked about the streets for the degradation of national taste, but also plays an important part in the manufacture of bonbons, the destruction of the human digestion, and the ultimate ruin of the dominant white European race. Only about a third of the water in a salt lake need be evaporated before the gypsum begins to be deposited in a solid layer over its whole bed; it is not till 93 per cent. of the water has gone, and only 7 per cent. is left, that common salt begins to be thrown down. When that point of intensity is reached, the salt, too, falls as a sediment to the bottom, and there overlies the gypsum deposit. Hence all the world over, wherever we come upon a bed of rock salt, it almost invariably lies upon a floor of solid gypsum.
The Caspian, being still a very respectable modern sea, constantly supplied with fresh water from the surrounding rivers, has not yet begun by any means to deposit salt on its bottom from its whole mass; but the shallow pools and long bays around its edge have crusts of beautiful rose-coloured salt-crystals forming upon their sides; and as these lesser basins gradually dry up, the sand, blown before the wind, slowly drifts over them, so as to form miniature rock-salt beds on a very small scale. Nevertheless, the young and vigorous Caspian only represents the first stage in the process of evaporation of an inland sea. It is still fresh enough to form the abode of fish and mollusks; and the irrepressible young lady of the present generation is perhaps even aware that it contains numbers of seals, being in fact the seat of one of the most important and valuable seal-fisheries in the whole world. It may be regarded as a typical example of a yet youthful and lively inland sea.
The Dead Sea, on the other hand, is an old and decrepit salt lake in a very advanced state of evaporation. It lies several feet below the level of the Mediterranean, just as the Caspian lies several feet below the level of the Black Sea; and as in both cases the surface must once have been continuous, it is clear that the water of either sheet must have dried up to a very considerable extent. But, while the Caspian has shrunk only to 85 feet below the Black Sea, the Dead Sea has shrunk to the enormous depth of 1,292 feet below the Mediterranean. Every now and then, some enterprising De Lesseps or other proposes to dig a canal from the Mediterranean to the Dead Sea, and so re-establish the old high level. The effect of this very revolutionary proceeding would be to flood the entire Jordan Valley, connect the Sea of Galilee with the Dead Sea, and play the dickens generally with Scripture geography, to the infinite delight of Sunday school classes. Now, when the Dead Sea first began its independent career as a separate sheet of water on its own account, it no doubt occupied the whole bed of this imaginary engineers’ lake — spreading, if not from Dan to Beersheba, at any rate from Dan to Edom, or, in other words, along the whole Jordan Valley from the Sea of Galilee and even the Waters of Merom to the southern desert. (I will not insult the reader’s intelligence and orthodoxy by suggesting that perhaps he may not be precisely certain as to the exact position of the Waters of Merom; but I will merely recommend him just to refresh his memory by turning to his atlas, as this is an opportunity which may not again occur.) The modern Dead Sea is the last shrunken relic of such a considerable ancient lake. Its waters are now so very concentrated and so very nasty that no fish or other self-respecting animal can consent to live in them; and so buoyant that a man can’t drown himself, even if he tries, because the sea is saturated with salts of various sorts till it has become a kind of soup or porridge, in which a swimmer floats, will he nill he. Persons in the neighbourhood who wish to commit suicide are therefore obliged to go elsewhere: much as in Tasmania, the healthiest climate in the world, people who want to die are obliged to run across for a week to Sydney or Melbourne.
The waters of the Dead Sea are thus in the condition of having already deposited almost all their gypsum, as well as the greater part of the salt they originally contained. They are, in fact, much like sea water which has been boiled down till it has reached
the state of a thick salty liquid; and though most of the salt is now already deposited in a deep layer on the bottom, enough still remains in solution to make the Dead Sea infinitely salter than the general ocean. At the same time, there are a good many other things in solution in sea water besides gypsum and common salt; such as chloride of magnesia sulphate of potassium, and other interesting substances with pretty chemical names, well calculated to endear them at first sight to the sentimental affections of the general public. These other by-contents of the water are often still longer in getting deposited than common salt; and, owing to their intermixture in a very concentrated form with the mother liquid of the Dead Sea, the water of that evaporating lake is not only salt but also slimy and fetid to the last degree, its taste being accurately described as half brine, half rancid oil. Indeed, the salt has been so far precipitated already that there is now five times as much chloride of magnesium left in the water as there is common salt. By the way, it is a lucky thing for us that these various soluble minerals are of such constitution as to be thrown down separately at different stages of concentration in the evaporating liquid; for, if it were otherwise, they would all get deposited together, and we should find on all old salt lake beds only a mixed layer of gypsum, salt, and other chlorides and sulphates, absolutely useless for any practical human purpose. In that case, we should be entirely dependent upon marine salt pans and artificial processes for our entire salt supply. As it is, we find the materials deposited one above another in regular layers; first, the gypsum at the bottom; then the rock-salt; and last of all, on top, the more soluble mineral constituents.
