by Guy Murchie
But there may still be more unknown than known species, particularly among the insects and microbes. Even sizable species are being discovered at a surprising rate: a new species of bird on an average of once a week, a new mammal nearly every fortnight, a new reptile or amphibian about twice yearly, a new insect about once an hour and every now and then a whole new phylum - the largest classification of animals - like that of a kind of worm with tentacles (Pogonofora) found on the ocean floor in 1964, then still another seaworm phylum (Gnathostomulida) in 1968. And if you think that anything as big as the legendary "abominable snowman" could not possibly exist yet remain unaccepted by science in this "advanced" age, remember that such hulking monsters as the square-lipped rhinoceros, largest of the rhino clan and second in size only to the elephant among land animals, was unknown until 1900, and also the huge brown bears of Kamchatka and Alaska (ten feet long and the biggest carnivores alive) unrecognized until two years earlier, while the mountain gorilla, largest of the apes, was only a myth before 1901, and the Komodo dragon, the tenfoot-long lizard known to kill and eat water buffaloes, was discovered by an airman downed in the East Indies in 1912. This list could be continued indefinitely through this century: the okapi, a kind of striped Congo "mule" added in 1900, the golden takin deer of China in 1911, the Yangtze dolphin in 1918, the giant panda first captured in 1936 ... none of them small but all somehow overlooked and unrecorded until our own time.
To anyone with imagination, it should be clear by now that there could easily be, and almost surely must be, more such creatures still lurking shyly and unknown in the jungles of central Africa, the vast Amazon basin or perhaps Malaya. Why not? Or would they more likely be on some lush island like New Guinea where, as recently as June 1954, patrol planes turned up completely unknown stone age tribes estimated to number 100,000, some of whose cultures may be more primitive than those of Neanderthal man? There are innumerable half-verified legends around the still sleepy Earth, I hear - like that of "the spotted mountain lion" and the "Nandi bear" in Kenya, of the Loch Ness monster in Scotland, the "marsupial tiger" and the super otter called a "bunyip" of Australia, the "kongamato" or flying dragon of Zambia, some of which may prove to be real. As may also an occasional wary descendant of the presumably extinct giant swamp reptiles, or of the woolly mammoths in Siberia (reportedly seen alive last in 1918), the 15-foot sloth of Patagonia, the wingless 11-foot moa of New Zealand, the perhaps even larger Madagascan roc (of Sinbad the Sailor fame) whose 13 1/2-inch egg has been found to hold 2 1/2 gallons - all of which are intermittently rumored to be, and any of which just might turn out to be, still alive.
As we will see again and again in this book, just about everything imaginable has been, is being, or may yet be tried out somewhere, somehow, in this extraordinary world we live in. In evidence of which I testify that the recognized nonlegendary animal kingdom has long since adopted and perfected: movement without muscles, sight without eyes, hearing without ears, smelling without a nose, thirst quenching without drinking, eating without a mouth, digestion without a stomach or excretion, reproduction without sex, thinking without a brain and life without rest, sleep or death. And of course there are dozens of well-established senses besides the familiar five, not counting artificial ones (like the barometer), vicarious ones (like the watchdog), or most of the natural new ones that are continuously evolving.
And should you be one of those conventional persons who thinks of parasites as abnormal or perhaps goes so far as to drat the varmints, you may be surprised to discover, as I did, that parasites live both inside and outside most organisms in all the kingdoms, which makes parasitism thoroughly normal along with its derivatives: hyperparasitism (the phenomenon of parasites whose hosts are parasites in turn), hyperhyperparasitism, hyper3-, hyper4-... and on up to hypern-. And not only is the sun a parasite of the Milky Way as the earth is a parasite of the sun and terrestrial life parasitic on the earth, but you are a parasite of civilization (of which this book is a small token in evidence); and your dog, cat, canary, mice or others parasitic on you have each their own domestic fleas or lice or mites, etc., all of which (like you) must harbor itinerant bacteria which in turn carry viruses as passengers and, more than likely, stowaways still undiscovered ... for it is not yet certain how many links such parasitic chains may have. Furthermore parasitism is part of the larger and even more complex subject of ecology or the interrelationship between all creatures and their total environments, which includes slavery, domestication, free sharing and a wide spectrum of bartering partnerships under the general heading of symbiosis. Parasitism may thus be a step toward brotherhood and even love, often becoming about as good in the long run for the host as for the parasite, both of whom tend to become dependent on each other under their unwritten but well-understood contract, as surely as you rely on your intestinal bacteria for digestion and vitamins or on your cat to suppress your mice.
In many such ways I see life deviously and imaginatively adapting itself to the world and to its own nature, shaping its form and behavior to the very Earth - to all the esoteric motions and melodies of the sphere. So it may be useful now to attend more closely the geography of animaldom - to observe more exactly how creatures evolve and function in relation to gravitation, to temperature, humidity, dynamic and chemical forces, light and the rhythms of days and seasons. Quite plainly, terrestrial life is part of the earth about as much as wheels and escapement are part of a clock. And, like a clock, the Earth turns, slowly but with order and cadence. Even more realistically, since Einstein has demonstrated the nonfundamental and illusory nature of space and time, the physical essence of Earth life may be termed a spherical biofilm rotating in gravitational, electromagnetic and nuclear fields - a sort of gyrating bubble of evolving potency, a cosmic node of ferment.
While this bubble of life is materially concentrated in the fifteen-mile-thick earth skin of sea, soil and densest air, it is fueled and fed from energy in the planet's core and mantle and from the sun and stars. And it is bound together not only by gravitational, electromagnetic and nuclear cohesion but also by a kind of surface tension of interdependence, of chemical and psychological needs and intellectual accelerations interlaced with mystic, sometimes explosive, spiritual forces.
From a chemical standpoint alone, animal life without plants to eat would starve quicker but no more surely than most plants would die without animals. Even minerals would be drastically disturbed without both these higher kingdoms. It has been calculated that photosynthesis in present terrestrial vegetation would literally consume all the carbon dioxide out of the atmosphere within a year or two if it were not replenished by smoke from fires, engine fumes and the exhalations of animals and other consumers or decomposers.
THE FACTORS OF SIZE AND GRAVITATION
Although, at first thought, any correlation between the size of Earth and the size of her animal inhabitants is farfetched, a little reflection reveals a law of nature that says the creatures of Earth really must be approximately sized and shaped to the planet through the effects of gravity and chemistry, which vary as the creatures are large or small, fat or thin. It was Galileo who first articulated this law as the Principle of Similitude and it explains why no animal as little as a mouse need worry about getting hurt if it falls off a cliff or out of an airplane at any height since its body surface amounts to a parachute in relation to its meager weight, while an elephant is likely to be killed falling ten feet because his 10,000 times greater surface is made negligible by his 1 million times greater relative weight. This is because any two-dimensional surface increases as a square, while the corresponding three-dimensional volume or weight increases as a cube. And it explains why insects need no lungs and algae need no leaves their simple spiracles and surfaces being ample enough to absorb all the oxygen or carbon dioxide their diminutive bodies need, while larger animals and
plants would suffocate without their vast breathing areas in lungs and leaves. And, since digestion too is a surface function (of the surf
ace of the intestines), it also explains why a ton of mice eats ten times as much as a ton of horses, and a ton of bacteria about ten times as much as a ton of mice.
Such inexorable disparities in size-surface ratios of course form a major geometric distinction between the microcosm and macrocosm, and their influence upon the forces and materials of Earth accounts for the size limits of its inhabitants, who could hardly walk on land if they were bigger than elephants or get enough to eat in the sea if much bulkier than whales or even stand still as trees if appreciably taller than a hundred meters. Furthermore, at the lower extremes, they could hardly be considered alive if their bodies contained less than a million atoms, this time not because of gravity but rather because of the uncertainties of random motion among individual atoms while their numbers remain too few to average each other into reliable order.
D'Arcy Thompson, who expressed similar concepts half a century ago in his classic book On Growth and Form, spoke of the form of any object as essentially a "diagram of forces" since "matter as such produces nothing, changes nothing, does nothing." Indeed he pointed out in some detail how physical forces create organic forms, from the hexagonal prisms of the honeycomb (which are merely cylinders under pressure) to the equiangular spirals of horns and shells, which permit drastic growth without a basic change of shape or even, in some cases, without so much as shifting their centers of gravity. In fact the very skeletons of creatures from microscopic radiolarians in the sea to the dolphin's skewed skull that may help him scull his way through the deep and to the cantilevered bones of beast and bird with their beautiful lines of tension and compression that are often mirror images of each other - all these are manifestations of stress upon growth by which nature creates form not so differently from the way the glassblower molds tubes and bulbs and vases by directing forces here and there in the space and time allowed.
The way in which earthly animals are molded by the earth in size or shape may be understood best of all perhaps by imagining what corresponding creatures would have to be like on other worlds. For instance, the gravity of a planet as big as Jupiter, with a force 2 1/2 times stronger than Earth's, would require any Jovian donkeys to be as stout as terrestrial elephants in order to hold themselves up, chickens to have legs like ostriches, pigs either to crawl like alligators or swim in the way of porpoises (whose name, not inappropriately, derived from "pork fishes"). But on a moon with gravity much weaker than on Earth, an elephant might scamper about on spidery legs or a hippopotamus jump like a grasshopper and, if such a moon could have an atmosphere (as one of Saturn's is known to have), possibly beasts as big as wolves would have developed batlike wings on which they could flit with nary a qualm after their prey.
Even on Earth as it is now, the ponderous elephant does not have any too easy a time of it, as is shown by the fact that of 352 known species of proboscideans (mastodons, mammoths, etc.) that in the last few million years have roamed the land, only two species survive: the African and Indian elephants. Significantly, their nearest, though remote, remaining cousins are the mermaidenly sea cow and the little Woodchucklike hyrax - which suggests the capriciousness of natural evolution in its apparently heroic attempts to cope with a maturing planet.
The elephant's biggest problem of course is that he is so big. Far larger than any other animal that still walks the earth, he not only needs pillars for legs but literally an acre of lung surfaces to absorb oxygen, an eight-foot trunk to reach his food, a massive heart to circulate blood and hundreds of feet of guts and complex digestive organs to assimilate nourishment from the hundreds of pounds of foliage and grass he eats during his daily sixteen hours of browsing. These complications of course are not what makes the elephant so big. Rather is it his bigness that makes the elephant so complicated.
And among the more serious limitations of his size is his inability either to run, trot or jump, for experts claim that a trench seven feet wide is completely impassable to him, even if his stride covers 6 1/2 feet. His top speed when enraged and charging has been clocked by a retreating jeep at just eighteen miles an hour.
Although the elephant's enormous size usually protects him from serious injuries by tiger, lion or buffalo and he has often been called "Lord of the Jungle," paradoxically some elephants have been panicked by Scotch terriers, ants and even by mosquitoes swarming upon their sensitive trunks. And they are notoriously susceptible to a great many afflictions, including nettle rash, seasickness and such human diseases as colds, pneumonia, mumps and diabetes. To cite perhaps their best-remembered case from history, of the fifty smallish `war elephants" that Hannibal drove from Cartagena through Spain, Gaul and over the Swiss Alps in 218 B.C., only eight lived to see Italy and fight the Romans. And of these but one (the only Indian elephant among them) survived the Apennines, then miraculously regained his health sufficiently to endure the long campaign of at least six great battles, amazingly returning after fifteen years in solitary triumph to the elephant training stables in Carthage. Since Caesar's time, however, the war elephant has been obsolete in Europe and Africa, his domesticated descendants (outside of Asia) relegated mainly to circuses and exhibitions.
Perhaps the elephant's destiny will lead him into a more aquatic life in future centuries for, as a vehicle of land transport, he has not found it possible to keep up with the truck or the water buffalo. Yet by erecting his trunk as a snorkel, he can march (not without some jitters) through rivers twelve feet deep, treading the bottom, and he has been known to swim continuously for six hours. The only serious setback suffered by an elephant swimming at sea to my knowledge was the case of a crazed one that thrashed about so much he attracted sharks, who chomped him into a skeleton in less than an hour. And there exists a convincing record of one Indian rogue who, seeming to adopt the slogan "Have trunk, will travel," one day left home and family to plunge purposefully into the sea, whereupon for twelve years he sashayed through a leisurely 200-mile island-hopping jaunt in the Bay of Bengal.
Certainly the buoyancy produced by immersion in water removes some of the disadvantages of excessive weight, as the dinosaurs knew and, more recently, the whales rediscovered when they evolved back to sea. The whales have adapted themselves to ocean life by stepping up their speed which, according to Froude's Law of the correspondence of speeds, tends to increase "in the ratio of the square root of the increasing length" - and by such changes as moving their nostrils upward to the top of their heads and disconnecting their lungs and windpipes from their mouths so they can swim underwater with jaws open to feed without fear of drowning. By such evolutionary advances bottlenosed whales have enabled themselves to submerge for two hours or to dive three quarters of a mile deep, as has been estimated from more than a dozen cases of whales getting their jaws tangled in cables. And the sea-lent speed has restored their power to jump so dramatically that more than once a blue whale weighing over a hundred tons has been seen to breach completely out of water. Yet when even a small whale comes close to shore he is in imminent danger of becoming cornered or stranded on a beach where, if the tide ebbs to leave him partly out of water, he is not only helpless but liable to suffocate when his lungs collapse under his no-longer-buoyant weight.
While the buoyancy of water is a blessing to whales, it can be a serious problem to some fish, for bodies suspended beneath its surface yet not resting on the bottom must cope with the inherent instability of their position. Most fish therefore are equipped with "swim bladders" containing fat or gas (mostly oxygen) which give them neutral buoyancy in the sea by making their average density equal to that of water, the bladders gradually absorbing or discharging matter as the fish goes deeper or shallower, thus enabling it to keep its balance in earthly gravitation. Indeed, if a fish wanders far from its normal depth, up or down, it has to face the very real risk of "falling" either upward or downward, the upward motion, if beyond control, eventually bursting its insides most unpleasantly out through its mouth. In this connection, did you know that the common cuttlebone (traditionally given pe
t birds to groom their beaks on) serves in life as the buoyancy tank of the cuttlefish, a squid cousin which by osmotic control can vary his Cuttlebone density from .5 to .8, thus surfacing or submerging at will like a submarine. And the beautifully helical chambered nautilus uses gas in one of its storied and stately chambers to the same not-always-purely-poetic end.
But although the balloon principle can thus readily handle earthly gravity in the sea, animals in aerial flight have not found buoyancy so easy to achieve. For some strange reason, no creature before man seems ever to have evolved anything approaching a bladder of hydrogen. And air, being about 800 times lighter than water, just will not support any very dense body unless it uses either some sort of a balloon or the active flying principle of deflecting the sky's substance to generate lift. Froude's Law, incidentally covering all kinds of locomotion explains why the ostrich does not fly since, being about 25 times as tall and long as a sparrow, he would have to move or square root of 25 or 5 times as fast. That is at about the speed of a small airplane, which necessarily has many times an ostrich's horsepower.