CHAPTER XXII

IMMUNITY AND CURATIVE INOCULATIONS

During the last twenty years the whole attitude of the study and investigation of disease-causing microbes has advanced from the preliminary step of merely identifying certain microbes as the causes of certain diseases to a further step, viz. that of attempting to defend the animal and the human body against their attacks in the manner already so finely started by Pasteur. For many years disease after disease was examined and found to be caused by special bacteria or other microbes. Even non-infectious diseases or diseases only communicable under very special conditions were found to be due to microbes, so that it is probable that all disease that is not due to congenital malformation or to mechanical injury, or to poison fabricated in the weapons of larger animals and plants, or by man himself, is due to microbes. "Life," says Lord Justice Moulton, "is one ceaseless war against these enemies, and the periods of our too-transient successes are known as health." One of the last diseases traced to microbes is that sad condition known as "infantile paralysis," by which so many of the brightest and best members of the community have been crippled, from childhood onwards, through life.

Of late we have been making rapid strides in arriving at a knowledge as to how Nature herself protects higher creatures from the excesses and exuberance of destructive microbes, and we are now able to see that it is in adopting her methods that our best hope of increasing that protection lies. Nature is satisfied if the efficacy of her defence is sufficient to save enough individuals to carry on the race. Man desires in the case of his own fellows to out-do Nature and to save all.

A century and a half ago, before the true character of infective disease was understood, it was observed that an individual who was attacked by the smallpox and recovered became incapable of receiving the infection again. He was "protected" or "immune." The practice of "inoculation" was introduced from the East by Lady Montague. The infectious matter was introduced from a smallpox patient into the person to be protected by rubbing it into a scarified part of the skin. A much less severe attack of smallpox was thus produced than that which usually followed the natural infection, which (though we do not know precisely its mode of entrance) is more widely spread through the blood. At the same time the condition of "immunity" after the attack was brought about with equal efficacy. When Jenner introduced inoculation with "cowpox" for the purpose of establishing "immunity" in the vaccinated person, inoculation with smallpox itself was a very usual practice. It was open to the objection that sometimes an unexpectedly violent attack of the disease was produced, resulting in death, and that the active infection was kept alive and ever present in the community. The notion with regard to the mode in which "immunity" was produced by either the Montacutian or Jennerian inoculation was, even after the general knowledge of microbes as the living contagion of disease had been arrived at, that the mild attack due to inoculation "used up" something in the blood—in fact, exhausted the soil, so that the infective matter or microbe could no longer flourish in the blood. And this view was accepted as the explanation of the "immunity" to the anthrax disease conferred on cattle and sheep by Pasteur's inoculations of weakened, but still actively growing, cultures of the anthrax bacillus. Another theory was that they produced something in the blood by their own life-processes which checked their further growth, just as yeast will not grow in wort in which it has produced 8 per cent. of alcohol, and as a fire may be choked by its own smoke or ashes.

We now know that both these explanations of "immunity" are incorrect. Nature provides at least three varieties of defence within the blood of higher animals against disease-producing microbes which have broken through the outer line of fortification, the skin. These three methods are effective in different cases (one in this disease, the other in that), and, on the whole, are sufficient to preserve the races of animals (including man) from complete destruction. These are (1) the production in the blood of an antidote to the toxin or poison elaborated by the invading microbe—an antitoxin, which chemically neutralises the toxin; (2) the production in the blood of the attacked animal of a "germicidal" poison which repels and kills the attacking microbes themselves (not merely neutralising their poisonous products); (3) the extermination of the intrusive, disease-producing microbes by a kind of police, which scour the blood channels and tissues and "eat up"—actually engulf and digest—the hostile intruders. These latter agents, actual particles of the living animal in which they exist, are the "eater-cells," or "phagocytes"—minute, viscid, actively moving cells, resembling the animalcules called "amoeba." They are only the one two-thousandth of an inch in diameter, and are known as the white or colourless corpuscles of the blood. They are far less numerous than the red blood-corpuscles, which are the agents for carrying oxygen, but there are eight thousand million of them in a large spoonful of blood. They are the really important agents in protecting us from microbes, since they not only engulf and digest and so destroy those intruders, but it is probable (not certain) that they also are the manufacturers of the antitoxins and of the germicidal poisons.

* * * * *

If these three defensive processes given us by Nature are in working order, that is to say, if we are "healthy," they should secure to us a sufficient "immunity"—at at any rate, "recovery"—from any attack of disease-producing microbes. But they are not in "unselected," widely ranging mankind always equal (in their unaided natural state) to their task.

The attempts to produce immunity by vaccination with weakened or localised disease germs is really an attempt to train and develop to a high point the activities of the phagocytes or eater-cells of the blood.

The introduction of antitoxins by injection of them into the blood (as in the treatment of diphtheria, lock-jaw, and snake-bite) is an attempt to bring to the rescue of a patient who would sooner or later produce his own antitoxins (but perhaps too late or in insufficient quantity) the similar antitoxin obtained from the blood of another animal which has been artificially made to produce in its blood an excessive quantity of that substance.

Mithridates, King of Pontus, was, according to ancient legend, in consequence of his studies and experiments, soaked with all kinds of poisons to which he had become habituated by gradually increasing doses, and he had at last reached a condition in which no poison could harm him, so that when he was captured by the Romans and wished to kill himself (which was the correct thing in those days for a fallen king to do), he wept because he was unable to get any poisons which would act upon him. He was "immune" to all poisons. This real or supposed immunity resulting from the introduction into the living body at intervals of a series of doses of a poison gradually increasing strength has been called "Mithridatism," and animals and men so treated have been said to be "mithradatized." The toleration of poisonous drugs—such as tobacco and alcohol, and even of mineral poisons, such as arsenic—was, until lately, regarded as merely a special exhibition of that habituation of "adaptation by use" which living things often show in regard to some of the conditions of their life. Unusual cold, unusual heat, unusual moisture, salinity or the reverse, unusual deprivation of food, unusual muscular effort may be tolerated by animals without injury provided that they have been "gradually accustomed" to the unusual thing, or, in other words, that the unusual has been gradually made the usual; so that there is a saying that eels after a time even get used to being skinned. There was no attempt to explain the details of this process of habituation; it was assumed to be a part of the general "educability" of living matter.

The study of the education of living matter, in regard to various conditions which can act upon it, has yet to be further carried out, but the way in which the poisons made by disease germs and the like, and the disease germs themselves, are dealt with in the blood and tissues has, on account of its urgent importance, from a medical point of view, been already profoundly studied by experimental and microscopic methods of late years. The old notion as to "mithridatism" was that an animal or a man would have to be separately prepared and "immunised" by habituation for every distinct kind of poison. We now know that this is not the usual way in which Nature confers immunity to poisons. Most astonishing, and at first sight magical or mysterious, powers exist in the living protoplasmic cells in and around the blood of man and higher animals, which enable their possessors to resist and combat the poison-producing microbes, and also the poison itself, of all kinds, by which the race is liable to be attacked.

Few of us realise what a wonderful and exceptional fluid the blood of a higher animal is. The Australian natives attach so little importance to it that they actually cut themselves and use their blood as a sort of paste for sticking decorative feathers on to a pole! The Papuans are more advanced, since they regard the flow of blood from a cut or graze as an evil portent. And some respect to the greatness and wonder of blood is shown by those persons among civilised peoples (more frequently men than women) who faint when they see blood, or even at the mention of its name! This stream of red fluid within us (of which an average man has about fifteen pints in his vessels) courses at a tremendous rate from the heart through all the endless branches and networks of arteries, capillaries and veins, and back to the heart. It feeds, cleanses, warms and takes "vital air" (the old name for oxygen gas) dissolved in it to every particle of our bodies, fresh and fresh at every pulse-beat as it rushes on. It not only absorbs crude digested food through the walls of the gut, but conveys it to where it is worked up and distributes the worked-up product. It removes the quickly used-up substances from every part, and the choke-damp or carbonic acid which would stop the whole machine, and kill us, were it not got rid of through the lungs as the blood hurries through the walls of these air-sacs, whilst other used-up materials are carried by it to the kidneys and passed out of the body through them. Every part of the body is brought into common life with every other part by this impetuous blood-stream—which is here, there, and everywhere, right round, and back again, in twenty-five seconds! It is obviously a very serious thing if a poison-producing microbe gets into this blood-stream and multiplies within it, or if poison-producing microbes lodge somewhere beneath the skin in a wound, and keep on discharging virulent poison into the blood! The mischief is spread all over the body at once.

It is not surprising, then, that the long course of natural selection and survival of the fittest has resulted in the fixing in the blood and the living cells immediately connected with it of extraordinary protective powers. The floating scavenger cells (eater-cells or phagocytes, first recognised as such and so named by Metchnikoff) are already found in the blood of quite simple animals in worms, shell-fish and insects. I have watched them with the microscope at work in transparent minute living water-fleas eating up, and digesting microbes which had got into the water-flea's blood. In higher animals what we call "inflammation" is a condition—the result of a new and advantageous mechanism—which consists in a local retarding of the blood-current, effected by the action of the nerves on the muscular walls of the blood-vessels, and the consequent escape of the eater-cells into the injured or infected tissue, there to eat up and destroy the injurious microbes or other particles. Special and remarkable properties—chemical activities of an extraordinary character—have been gradually developed in the floating phagocytes and in similar non-floating fixed cells over which the blood flows.

These special chemical activities are of several distinct kinds. The first is the power to convert the poison of a microbe into a destroyer of that poison—toxin into antitoxin. The atoms of these poisons are elaborately composed combinations of the organic elements. By a "shake" or a "twist" (so to speak) administered by the living cells of the blood the combination is altered, and the toxin becomes an antitoxin, destroying by chemically combining with it the very toxin from which it was formed. This is a far more efficacious method than the supposed mithridatic "habituation" or "toleration" of a poison, with small doses of which you have to be gradually prepared. The healthy blood converts any one of a large series of microbe poisons into antitoxins. It is true that apparent "opposites" are often closely allied in Nature. Evil smells and tastes are closely allied to sweet perfumes and flavours, and what is healthy and agreeable to some men acts as virulent poison to others (e.g. shell-fish, egg, quinine, opium). The smallest change in the substance administered or the smallest difference in the living substance of an individual (what is called "idiosyncrasy") makes all the difference between "poison" and "meati."

If the phagocytes and similar cells in the blood of a man or animal exposed to the poison produced by localised microbes (such as those of tetanus, diphtheria and septic growths) cannot produce enough antitoxin so as to quickly destroy the poison, we can, and do, nowadays, save his life, by injecting into his blood the required antitoxin, obtained from another animal which we have caused (by injection of the toxin) to produce the antitoxin in excess. That is one sort of "immunity" or "resistance" which we can confer, and is largely in use at the present day—the "antitoxin" treatment.

The second poison-repelling chemical activity of the blood, produced by the living cells in and about it, consists in the blood becoming directly poisonous to injurious microbes. It becomes "bactericidal," produces a bactericidal poison (called an alexin) which is usually present in normal blood, but is greatly increased when large numbers of certain poisonous microbes (e.g. those of typhoid fever) get into the blood. Again, by other chemical substances produced in it, the blood may, without actually killing the invading bacteria, only paralyse them, and cause them to "agglutinate" (that is, to adhere to one another as an inactive "clot" or "lump"). As the "agglutinating" poison is peculiar (or nearly so) for each kind of microbe, we can tell whether a patient has typhoid by drawing a drop of his blood into a tube, and adding some fresh living typhoid bacilli to it. If the patient had typhoid he will have begun to form the "typhoid-agglutinating" or "typhoid-paralysing" poison in his blood, and the experiment will result in the "agglutination" (sticking together in a lump) of the typhoid bacilli. And so we prove, in a doubtful case, that the patient has typhoid.

The third chemical activity of the blood in dealing with poisonous microbes is also one which is conferred upon it by its living cells when excited by the presence of those microbes. It is the production of a "relish" (for so it must be called) which attaches itself to the microbes and renders them attractive to the eater-cells (the phagocytes), so that those swarming amoeba-like floating particles at once proceed to engulf the microbes with avidity. In the absence of the relish (the Greek word for it used by Sir Almroth Wright, its discoverer, is "opsonin"), the eater-cells are sluggish—too sluggish—in their work. They resemble a child who will not eat dry toast, or, at best, only slowly, but will devour rapidly many pieces when the toast is buttered. It is of the utmost importance to us that our white corpuscles, or eater-cells, should not be sluggish but greedy.

There are some microbes which will produce deadly poison if grown in the clear fluid (serum) of the blood of an animal (as, for instance, the cholera-microbe when grown in the serum of the frog's blood), yet when inoculated living into the blood of that animal never cause the slightest illness! Why? Because they are at once eaten by the vigilant phagocytes of the blood before they can produce any appreciable amount of poison. That is easily demonstrated by experiment. Our main means of defence against microbial disease, says Metchnikoff—though cleanliness and precaution against access of microbes are all very well in their way—is the activity of our phagocytes. Now it appears that just as in the other cases I have been considering, so in the production of "relish," the power to produce it resides in the blood (and perhaps the cells of its vessels), but is not set at work until the enemy is in the blood. Suppose there is an infection, an invasion of the blood and tissues by one or other disease-causing microbe. Gradually if the body is healthy the "relish" is produced and becomes attached to the invading microbes. The phagocytes swallow them greedily and make an end of the invasion.

It is proved that this aroused avidity of the phagocytes is due to no change in the phagocytes themselves; since if they are transferred to the serum of a normal man they show no such predilection for the special invading microbe. The "opsonin," or "relish," is something exuded into or produced in the blood fluid when the attacking microbe arrives. It attaches itself to them: that is the essential fact. In many of us the phagocytes are not at a given moment so "avid" of this or that disease-microbe as they should be in order to protect us from its multiplication and poison production. But it is found that by injecting boiled and cooled (therefore dead) microbes of a particular kind into the blood of a man, you can start the production of the "relish" appropriate to that kind. The dead microbes answer this purpose; they excite the production of the opsonin appropriate to them and yet are not themselves dangerous, since they are dead. When subsequently (or possibly concurrently in small quantity) living microbes of the same disease enter the blood, the opsonin is ready for them. They are, to put it picturesquely, like oysters at the oyster-bar, peppered and vinegared "in no time," and then swallowed by the phagocytes by the dozen. This seems almost too comic a view of the deadly struggle of man and higher animals for health and freedom from the swarming pests which everywhere invade him. Yet it is correct, and involves a simple and fundamental truth. Our properties and appetites are but the sum of those of the protoplasmic organisms—the cells—of which we are built up. Our need for a relish with oysters is the same thing as the need of the phagocyte for a relish with its microbes, not something "poetically" compared to it. The story of "the oysters and the carpenter" might be replaced by that of "the microbes and the phagocyte." The saying, "Fine words butter no parsnips," finds a parallel in the remark that "The drinking of drugs does not opsonise microbes."

Half-way between us and the amoeba-like unicellular organisms we find the earth-worm preparing his piece of lettuce (as Darwin showed) with a juice exuded from his mouth, a "relish" reminding one of the Kava drink of the South Sea Islanders. To "opsonise" or render attractive by the application of chemical "relish" is a proceeding which we find in operation in the feeding of the minute colourless corpuscles which engorge the still more minute bacteria—and also in the preparation of their food by various lower animals, and finally in the elaborate flavouring and cooking of his food by civilised man!



CHAPTER XXIII

THE STRANGE STORY OF ANIMAL LIFE IN NEW ZEALAND

New Zealand consists of two islands, together more than 1,000 miles long and of about 200,000 square miles area. It is 1,000 miles distant from New Caledonia, the nearest island of any considerable size, and is 1,500 miles from the great Continental island of Australia. There is no other island in the world so large and at the same time so remote from other considerable tracts of land. Australia is closely connected by island groups at a distance of only 100 miles to Asia. The isolation of New Zealand is unique. The seas around it are of vast depth and of proportionately great age. During the chalk period—before the great deposits and changes of the earth's face which we assign to the Tertiary period—New Zealand consisted of a number of small scattered islands, which gradually, as the floor of the sea rose in that part of the world, became a continent stretching northward and joining New Guinea. In that very ancient time the land was covered with ferns and large trees. Birds (as we now know them) had only lately come into existence in the northern hemisphere, and when New Zealand for a time joined that area the birds, as well as a few lizards and one kind of frog, migrated south and colonised the new land. It is probable that the very peculiar lizard-like reptile of New Zealand—the "tuatara" or Sphenodon—entered its area at a still earlier stage of surface change. That creature (only 20 in. long) is the only living representative of very remarkable extinct reptiles which lived in the area which now is England, and, in fact, in all parts of the world, during the Triassic period, further behind the chalk in date than the chalk is behind our own day. For ages, this "type" with its peculiar beak-like jaws, has survived only in New Zealand. Living specimens have been brought to this country, and are to be seen at the Zoological Gardens in Regent's Park. Having received, as it were, a small cargo of birds and reptiles, but no hairy, warm-blooded quadruped, no mammal, New Zealand became at the end of the chalk-period detached from the northern continent, and isolated, and has remained so ever since. Migratory birds from the north visited it, and at a late date two kinds of bat reached it and established themselves.

Thus we are prepared for the very curious state of things in this large tract of land. Looking at New Zealand as it was a thousand years ago, we find there were no mammals living on it excepting a couple of bats and the seals (so-called sea lions, sea elephants, and others) which frequent its coasts. There were 180 species of birds, and many of these quite peculiar to the island. Many of the birds showed in the absence of any predatory enemies—there being no carnivorous quadrupeds to hunt them or their young—a tendency to lose the power of flight, and some had done so altogether. The gigantic, wingless Moas—allied to the ostrich and the cassawary—had grown up there, and were the masters of the situation. There were many species of these—one of great height—one fourth taller than the biggest known ostrich; others with short legs of monstrous thickness and strength. Allied to these are the four species of Kiwi or apteryx, still existing there. They are very strange wingless birds, about the size of a large Dorking fowl. The Kiwis are still in existence, but the Moas and some of the other flightless birds have died out since the arrival of the Maori man, who killed and ate them.

A bird which was believed sixty years ago both by the natives and white men to have become extinct, the Takahe, or Notornis, was known by its bones and from the traditions of the natives. Much to the delight of naturalists, four live specimens of it were obtained at intervals in the last century, the last as late as 1898. The beautiful dark plumage and thick and short beak, which is bright red, as are the legs, are well known from the two specimens preserved in the Natural History Museum. The Notornis is a heavy, flightless "rail." Rails are remarkable for their size and variety in New Zealand, where there are twenty species, some of them very sluggish in flight, or like Notornis, flightless (the wood hens). Amongst the flightless birds of New Zealand is a duck, as helpless as the heaviest farmyard product, and yet a wild bird, and then there are the penguins, which swim with their wings, but never fly, and belong entirely to the southern hemisphere. Many species are found on the shores of New Zealand. Other noteworthy birds of New Zealand are the twelve kinds of cormorants, the wry-bill plover, the only bird in the world with its beak turned to one side, the practically flightless Kakapo, or ground parrot (Stringops), the Huia, a bird like a crow in appearance, whose male has a short straight beak, whilst the female has a long one, greatly curved; the detested Kea, the parrot which kills the sheep, introduced by the colonists, by digging out with its beak from their backs the fat round the kidneys; also very peculiar owls and wrens, and the fine singing bell-birds.

The peculiarity of the indigenous animals of New Zealand is seen not only in the absence of mammals and the abundance of remarkable birds, many of them flightless, but also in the fact that there are no snakes in this vast area—no crocodiles, no tortoises—only fourteen small kinds of lizard (seven Geckoes and seven Skinks), and only one species of frog (and that only ever seen by a very few persons)! There were fish in the rivers when settlers arrived there, but none very remarkable. Insects and flies of every kind, scorpions, spiders, centipedes, land-snails and earth-worms were all flourishing in the forests of New Zealand a thousand years ago, serving in large measure as the food of birds, fish and lizards. The great island continent of Australia, 1,500 miles away, is peculiar enough in its living products, quite unlike the rest of the world in its egg-laying duck-mole and spiny ant-eater, and in its abundant and varied population of pounched mammals or marsupials, emphasized by the absence (except for two or three peculiar little mice and the late-arrived black-fellow and bush-dog) of the regular type called "placental" mammals which inhabit the rest of the world. The rest of the world except New Zealand! Strange as Australia is, New Zealand is yet stranger. Long as the isolation of Australia has endured, and archaic and primitive in essential characters as is its living freight of animals and plants navigated (as it were) in safety and isolation to our present days, yet New Zealand has a still more primitive, a more ancient cargo. When we divide the land surfaces of the earth according to their history as indicated by the nature of their living fauna and flora and their geological structure, and the fossilised remains of their past inhabitants, it becomes necessary to separate the whole land surface into two primary sections: (a) New Zealand, and (b) the rest of the world, "Theriogoea," or the land of beasts (mammals). Then we divide Theriogoea into (1) the land of Marsupials (Australia) and (2) the land of Placentals (the rest of the world). This last great area is divisible according to the same principles into the great northern belt of land, the Holarctic region and the (three not equally distinct) great southward-reaching land surfaces—the Neo-tropical (South America), the Ethiopian (Africa, south of the Sahara), and the Oriental (India and Malay).

The bird-ruled quietude of New Zealand was disturbed 500 years ago by the arrival of the Polynesian Islanders, the Maoris, in their canoes. They brought with them three kinds of vegetables which they cultivated, a dog and a kind of rat. The dogs soon died out, but the rat has remained, and is considered to have done little or no harm. It was not one of the destructive proliferous rats of the northern hemisphere. The Maoris hunted the big birds—the Moas and others—for their flesh, and ate their eggs, and it is probable that they caused or accelerated the extinction of the Moa and two or three other birds. In the north island they nearly exterminated the white heron, the plumes being valued by them. On the whole, very little damage was done to the natural products of the islands by the Maoris. "It was with the advent of the Europeans," says Mr. John Drummond, F.L.S., in his interesting and well-illustrated book on 'The Animals of New Zealand,' "that destruction began in earnest. It seemed as if they had been commanded to destroy the ancient inhabitants." They killed right and left, and, in addition, burnt up the primaeval forests and bushes till a great part of the flora was consumed. It was never a very varied or strong one, consisting only of some 1,400 species, which are now in large proportion vanishing, whilst 600 species of plants, most of them introduced accidentally rather than intentionally by the European settlers, have taken their place.

Here I may state the great principle which, in regard to plants as well as animals, determines the survival of intruders from one region to another. It appears that setting aside any very special and peculiar adaptations to quite exceptional conditions in a given area, the living things, whether plants or animals, which are brought to or naturally arrive at such an area, survive and supplant the indigenous plants and animals of that area, if they themselves are kinds (species) produced or formed in a larger or more variegated area; that is to say, formed under severer conditions of competition and of struggle with a larger variety of competitors, enemies and adverse circumstances in general. Thus, the plants of remote oceanic islands are destroyed, and their place and their food are taken by the more hardy "capable" plants of Continental origin. And, in accordance with the same principle, as Darwin especially maintained, the plants of the northern hemisphere, produced as they are in a wide stretching belt of land—Europe, temperate Asia, and North America—always push their way down the great southern stretches of land (by cool mountain roadways), and when they have arrived in the temperate regions of the southern hemisphere, they have at various geological epochs starved out, taken the place of, or literally "supplanted" the native southern flora, which in every case has been formed on a narrow, restricted and peninsula-like area. The same greater "potency" of the animals of the Holartic region has in the past established them as intruders into South America, Ethiopia and India, and has led to the inevitable survival of the animal of the large area when brought into contact with the animal of the small and restricted area. Applying these principles to New Zealand, we see that no country, no area of land, could have a worse chance for the survival of its animal and vegetable children than that mysterious land, isolated for many millions of years in the ocean, the home of the Tuatara, solitary survivor of an immensely remote geologic age, the undisturbed kingdom of huge birds, so easy-going that they have ceased to fly, and have even lost their wings!

The first European animals to settle there were the pigs benevolently introduced into New Zealand by Captain Cook. They multiplied apace, served for food and sport both to the natives and the early settlers, and destroyed the ancient Triassic reptile, the Tuatara, which only survives now on rocky islands near the coast. In less than a hundred years the settlers had introduced sheep and cattle, and looked upon the abounding pigs as a scourge. In 1862, pig-hunters were employed to destroy them—three hunters would kill 20,000 pigs in a year. Dogs, cats and the European rats came in early with the settlers, and destroyed the flightless birds, driving them for shelter to the mountains. As the settlers increased they shot down millions of birds of all kinds, and burnt up grass, shrub, and bush. At last, a few years ago, the Government established three islands as "sanctuaries," where many of the more interesting birds survive, and are increasing.

Besides cattle and sheep (which have flourished exceedingly) the colonists introduced rabbits, pheasants and the honey-bee, and later on quails, hares, deer, and trout. Clover depends on bees for its fertilisation and seeding. White clover, taken over there for pasture, did not seed in New Zealand until the honey-bee was imported in 1842, and later, as they could not seed red-clover without it, the colonists had to introduce the humble-bee, and the red-clover now also seeds freely and the imported farm-beasts have their accustomed food. Besides the animals already named, the colonists have introduced ferrets and weasels, to reduce the destructive excess of the imported rabbits; and they, whilst failing to subdue the rabbits, have themselves become a serious nuisance. Of small birds there were introduced the house-sparrow, which is too prolific, and is hated by the farmers; the greenfinch, a pest; the bullfinch, a failure. The introduced skylark and the blackbird (alas! poor colonists) are not the joy of New Zealanders—the farmers hate them. The European settlers had the audacity to introduce also the most beautiful and beloved of all birds, our own perfect "Robin Redbreast," and they add want of manners to their violent and uncalled-for hospitality by speaking ill of this sweetest and brightest of living things. After this, I am rather glad to report that the esteemed table-delicacies, pheasants and partridges, don't get on well in New Zealand; nor do turtle-doves. The thrush is spreading and meets with the approval of the hypercritical New Zealander. The hedge-sparrow, the chaffinch and the goldfinch have flourished abundantly, but the linnet has failed. A very interesting and important problem for New Zealand naturalists to solve is that as to why one bird succeeds in their remote land and another does not. The British trout have grown to an enormous size and are destroying all other fresh-water life. Imported red-deer flourish, and are shot with great satisfaction by the colonists. The American elk has been introduced in the South Island, and the mountain goats—the ibex and the thar—are to be acclimatized in the mountains, so that unnatural sport may flourish in this ancient land of quiet and of wondrous birds, turned topsy-turvy by enlightened man.



CHAPTER XXIV

THE EFFACEMENT OF NATURE BY MAN

Very few people have any idea of the extent to which man since his upgrowth in the late Tertiary period of the geologists—perhaps a million years ago—has actively modified the face of Nature, the vast herds of animals he has destroyed, the forests he has burnt up, the deserts he has produced, and the rivers he has polluted. It is, no doubt, true that changes proceeded, and are proceeding, in the form of the earth's face and in its climate without man having anything to say in the matter. Changes in climate and in the connections of islands and continents across great seas and oceans have gone on, and are going on, and in consequence endless kinds of animals and plants have been, some extinguished, some forced to migrate to new areas, many slowly modified in shape, size, and character, and abundantly produced. But over and above these slow irresistible changes there has been a vast destruction and defacement of the living world by the uncalculating reckless procedure of both savage and civilised man which is little short of appalling, and is all the more ghastly in that the results have been very rapidly brought about, that no compensatory production of new life, except that of man himself and his distorted "breeds" of domesticated animals, has accompanied the destruction of formerly flourishing creatures, and that, so far as we can see, if man continues to act in the reckless way which has characterised his behaviour hitherto, he will multiply to such an enormous extent that only a few kinds of animals and plants which serve him for food and fuel will be left on the face of the globe. It is not improbable that even these will eventually disappear, and man will be indeed monarch of all he surveys. He will have converted the gracious earth, once teeming with innumerable, incomparably beautiful varieties of life, into a desert—or, at best, a vast agricultural domain abandoned to the production of food-stuffs for the hungry millions which, like maggots consuming a carcase, or the irrepressible swarms of the locust, incessantly devour and multiply.

Another glacial period or an overwhelming catastrophe of cosmic origin may fortunately, at some distant epoch, check the blind process of destruction of natural things and the insane pullulation of humanity. But there are, it seems probable, many centuries of what would seem to the men of to-day deplorable ugliness and cramping pressure in store for posterity unless an unforeseen awakening of the human race to the inevitable results of its present recklessness should occur. Whatever may be the ultimate fate of the earth under man's operations, we should endeavour at this moment to delay, as far as possible, the hateful consummation looming ahead of us.

It is interesting to note a few instances of man's destructive action. Even in prehistoric times it is probable that man, by hunting the mammoth—the great hairy elephant—assisted in its extinction, if he did not actually bring it about. At a remote prehistoric period the horses of various kinds which abounded in North and South America rapidly and suddenly became extinct. It has been suggested, with some show of probability, that a previously unknown epidemic disease due to a parasitic organism—such as those which we now see ravaging the herds of South Africa—found its way to the American continent. And it is quite possible that this was brought from the other hemisphere by the first men who crossed the Pacific and populated North America.

To come to matters of certainty and not of speculation, we know that man by clearing the land, as well as by actively hunting and killing it, made an end of the great wild ox of Europe, the aurochs or urus of Caesar, the last of which was killed near Warsaw in 1627. He similarly destroyed the bison, first in Europe and then (in our own days) in North America. A few hundred, carefully guarded, are all that remain in the two continents. He has very nearly made an end of the elk in Europe, and will soon do so completely in America. The wolf and the beaver were destroyed in these British Islands about 400 years ago. They are rapidly disappearing from France, and will soon be exterminated in Scandinavia and Russia and in Canada. At a remote prehistoric period the bear was exterminated by man in Britain and the lion driven from the whole of Europe, except Macedonia, where it still flourished in the days of the ancient Greeks. It was common in Asia Minor a few centuries ago. The giraffe and the elephant have departed from South Africa before the encroachments of civilised man. The day is not distant when they will cease to exist in the wild state in any part of Africa, and with them are vanishing many splendid antelopes. Even our "nearest and dearest" relatives in the animal world, the gorilla, the chimpanzee and the ourang, are doomed. Now that man has learnt to defy malaria and other fevers the tropical forest will be occupied by the greedy civilised horde of humanity, and there will be no room for the most interesting and wonderful of all animals, the man-like apes, unless (as we may hope in their case, at any rate) such living monuments of human history are made sacred and treated with greater care than are our ancient monuments in stone. Smaller creatures, birds like the dodo and the great auk and a whole troop of others less familiar, have disappeared and are disappearing under the human blight. Even some beautiful insects—the great copper butterfly and the swallow-tail butterfly—have been exterminated in England by human "progress" in the shape of the drainage of the Fen country.

But the most repulsive of the destructive results of human expansion is the poisoning of rivers, and the consequent extinction in them of fish and of well-nigh every living thing, save mould and putrefactive bacteria. In the Thames it will soon be a hundred years since man, by his filthy proceedings, banished the glorious salmon, and murdered the innocents of the eel-fare. Even at its foulest time, however, the Thames mud was blood-red (really "blood-red," since the colour was due to the same blood-crystals which colour our own blood) with the swarms of a delicate little worm like the earth-worm, which has an exceptional power of living in foul water, and nourishing itself upon putrid mud. In old days I have stood on Hungerford Suspension Bridge and seen the mud-banks as a great red band of colour, stretching for a mile along the picture when the tide was low. In smaller streams, especially in the mining and manufacturing districts of England, progressive money-making man has converted the most beautiful things of nature—trout streams—into absolutely dead corrosive chemical sewers. The sight of one of these death-stricken black filth-gutters makes one shudder as the picture rises, in one's mind, of a world in which all the rivers and the waters of the sea-shore will be thus dedicated to acrid sterility, and the meadows and hill-sides will be drenched with nauseating chemical manures. Such a state of things is possibly in store for future generations of men! It is not "science" that will be to blame for these horrors, but should they come about they will be due to the reckless greed and the mere insect-like increase of humanity.

* * * * *

In the destruction of trees and all kinds of plants man has deliberately done more mischief than in the extermination of animals. By inadvertence he has completely abolished the strange and remarkable trees and shrubs of islands—such as St. Helena—where the herbivorous animals introduced by him have made short work of the wonderful native plants isolated for ages, and have completely exterminated them, so that they are "extinct." We have just had the opportunity of studying one of the few oceanic islands—"Christmas Island" (forty square miles in area)—untouched by man until thirty years ago. It lies 200 miles south of Java. Its native inhabitants, plants and animals were carefully examined, and specimens secured twenty years ago. There were then no human inhabitants, and the island was rarely visited. It was, however, about twelve years ago handed over by its proprietors to some thousand Chinamen to dig and ship the 15,000,000 tons of valuable "phosphate" (at a profit of a guinea a ton), which forms a large part of its surface. And now from time to time we shall have reports of this result of contact with man, and through him with all the plagues and curses of the great world. Already a remarkable shrew-mouse and two native species of rat, peculiar to the island, have disappeared. Dr. Andrews ("Proceedings of the Zoological Society," February 2nd, 1909), who has twice explored the island, gives evidence that this is caused by a parasitic disease (due to a trypanosome like those which cause sleeping-sickness and various horse and cattle diseases) introduced by the common black rats from the ships which now frequent the island. The further progress of destruction will be carefully and minutely observed and recorded—but not arrested!

It is, however, in cutting down and burning forests of large trees that man has done the most harm to himself and the other living occupants of many regions of the earth's surface. We can trace these evil results from more recent examples back into the remote past. The water supply of the town of Plymouth was assured by Drake, who brought water in a channel from Dartmoor. But the cutting down of the trees has now rendered the great wet sponge of the Dartmoor region, from which the water was drawn all the year, no longer a sponge. It no longer "holds" the water of the rainfall, but in consequence of the removal of the forest and the digging of ditches the water quickly runs off the moor, and subsequently the whole countryside suffers from drought. This sort of thing has occurred wherever man has been sufficiently civilised and enterprising to commit the folly of destroying forests. Forests have an immense effect on climate, causing humidity of both the air and the soil, and give rise to moderate and persistent instead of torrential streams. Spain has been irretrievably injured by the cutting down of her forests in the course of a few hundred years. The same thing is going on, to a disastrous extent, in parts of the United States. Whole provinces of the Thibetan borders of China have been converted into uninhabitable, sandy desert, where centuries ago were fertile and well-watered pastures supporting rich cities, in consequence of the reckless destruction of forest. In fact, whether it is due to man's improvident action or to natural climatic change, it appears that the formation of "desert" is due in the first place to the destruction of forest, the consequent formation of a barren, sandy area, and the subsequent spreading of what we may call the "disease" or "desert ulcer," by the blowing of the fatally exposed sand and the gradual extension, owing to the action of the sand itself, of the area of destroyed vegetation. Sand-deserts are not, as used to be supposed, sea-bottoms from which the water has retreated, but areas of destruction of vegetation—often (though not always) both in Central Asia and in North Africa (Egypt, etc.), started by the deliberate destruction of forest by man, who has either by artificial drainage starved the forest, or by the simple use of the axe and fire cleared it away.

The great art of irrigation was studied and used with splendid success by the ancient nations of the near East. They converted deserts into gardens, and their work was an act of compensation and restitution to be set off against the destructive operations of more barbarous men. But they, too, long ago were themselves destroyed by conquering hordes of more ignorant but more war-like men, and their irrigation works and the whole art of irrigation perished with them. One of the absolutely necessary works to be carried out by civilised man, when he has ceased to build engines of war and destruction, is the irrigation of the great waterless territories of the globe. A little home-work of the kind has been carried on in Italy regularly year by year since the days of Leonardo da Vinci, and our Indian Government is slowly copying the Italian example. In Egypt we have built the great dam of Assouan, whilst in Mesopotamia it is proposed to re-establish the irrigation system by which it once was made rich and fertile. But, as has lately been maintained by Mr. Rose Smith in his book, "The Growth of Nations," the vast possibilities of irrigation have not yet been realised by the business men of the modern world. Millions of acres in the warmer regions of the earth now unproductive can be made to yield food to mankind and rich pecuniary profits to the capitalists who shall introduce modern engineering methods and a scientific system of irrigation into those areas.

The whole problem of the increase of the more civilised races and the necessary accompanying increase of food-production depends for its solution on the speedy introduction of irrigation methods into what are now the great unproductive deserts of the world.



CHAPTER XXV

THE EXTINCTION OF THE BISON AND OF WHALES

The almost complete and very sudden disappearance of the bison in North America thirty years ago does not seem to have been due simply to the slaughter of tens of thousands of these creatures by men who made a commerce of so-called "buffalo-rugs." These "hunters" miscalled the unhappy bison, which is not a buffalo, nor at all like that creature, just as they gave the name "elk" to the great red deer (the wapiti), although there was a real elk, the so-called "moose," staring them in the face. The sudden extinction of the bison resulted partly from the slaughter and partly from the breaking up of the herds and the interference with their free migration by the trans-continental railway. An interesting discovery made only this year, in regard to the closely allied European bison, suggests that disease may also have played a part in the destruction of the North American bison. A few hundred individuals of the European bison are all that remain at this day. Some are carefully preserved by the Emperor of Russia in a tract of suitable country in Lithuania and another herd exists in the Caucasus. Some of the Lithuanian bison have lately been dying in an unaccountable way, and on investigating a dead individual a Russian observer has discovered a "trypanosome" parasite in the blood. The trypanosomes are microscopic corkscrew-like creatures, of which many kinds have become known within the last ten or fifteen years. They are "single cells"—that is to say, "protoplasmic" animalcules of the simplest structure—provided with a vibrating crest and tail by means of which they swim with incessant screw-like movement through the blood. They rarely exceed one thousandth of an inch in length exclusive of the tail. The poisons which they produce by their life in the blood are the cause of the sleeping-sickness of man (in tropical Africa), of the horse and cattle disease carried by the tsetze fly, and of many similar deadly diseases—a separate "species" being discovered in each disease. A peculiar species is found in the blood of the common frog, and another in that of the sewer-rat. The last discovery of a "trypanosome" is that of one in the blood of the African elephant, announced to the Royal Society by Sir David Bruce.

It is a matter of great interest that a trypanosome has been found in a death-stricken herd of European bison. It suggests that one of the causes of the disappearance of the bison, both in Europe and America, may be the infection of their blood by trypanosomes, and that possibly, whilst a freely migrating and vigorous herd would not be extensively infected, a dwindled and confined herd may be more liable to infection, and that thus the final destruction of an already decadent animal may be brought about. It would now be a matter of extreme interest to ascertain whether the few dwindled herds of bison in North America are infected by trypanosomes, and no doubt we shall soon receive reports on the subject.

A most interesting branch of this subject of the unthinking extermination of great animals by man is that of the extermination of whales. Man is worrying them out of existence. Some are already beyond saving. It would be interesting to know whether there are trypanosomes or other blood-parasites in whales. I suppose that no one has an ill-feeling towards whales. Most of us have never seen a whale, either alive or in the flesh—only a skeleton. I have seen a live whale or two off the coast of Norway; and I once, in conjunction with my friend Moseley, when we were students at Oxford, cut up one, 18 ft. long, which had been exhibited for three weeks during the summer in a tent on the shores of the Bristol Channel, where we purchased it. The skeleton of that whale is now in the museum at Oxford, but happily the smell of it exists only in my memory. The late Mr. Gould, who produced such beautifully illustrated books on birds, told me that he once fell into the heart of a full-sized whale, which he was cutting up. He narrowly escaped drowning in the blood. The whale was not very fresh, and Mr. Gould was unapproachable for a week.

An immense number of whales are killed every year for their oil, and their highly nutritious flesh is wasted. There was an attempt some years ago to make meat extract from it. Some which was brought to me reminded me of the whale on the shores of the Bristol Channel. I do not know if the extract has proved palatable to other people. The Norwegians are specially expert in killing whales. They have been allowed to set up "factories" on the west coast of Ireland and in the Shetlands, where they kill whales with harpoons fired from guns, cut them up, and boil down the fat.

Whales are warm-blooded creatures which suckle their young, and have been developed in past geological times from land animals—the primitive carnivora—which were also the ancestors of dogs, bears, seals and cats. Whales have lost the hind limbs altogether and developed the forelegs into fingerless flippers, whilst the tail is provided with "flukes" like the fins of a fish's tail in shape, but horizontal instead of vertical. The whole form is fish-like, the skin smooth and hairless. It is a remarkable conclusion arrived at by the investigators of the remains of extinct animals that a little four-legged creature the size of a spaniel, and intermediate in character between a hedgehog and a dog, was the common ancestor from which have been derived such widely different creatures as the whale and the bat, the elephant and the man. We can at the present day trace with some certainty the gradual modifications of form by which in the course of many millions of years the change from the primitive, dog-like hedgehog to each of those four living "types" has proceeded.

The whales of to-day are divided into the toothed whales and the whalebone whales. The great cachalot or sperm whale is captured, chiefly in the Southern Ocean, and killed in large numbers for the sake of the "spermaceti," or "sperm oil," which forms the great mass of its head, but he is so fierce and active that he is not easily captured, and is not in immediate danger of extinction. The smaller toothed whales, the killers, dolphins, and porpoises (though one of them—the bottle-nosed whale—is being killed out), are not as yet seriously threatened by commercial man. But the whalebone whales are in a parlous state. The Right whales, as they are called, are the chief of these. They are huge creatures, 60 ft. in length, with an enormous head: it is as much as one third of the total length in the Greenland whale. Besides the Greenland species there are four other "right whales," which may be considered as four varieties of one species. The head is not quite so large in them. The Biscay whale is one of them, and was hunted until it was exterminated in the Bay of Biscay, when the whalers, extending their operations further and further north, came upon the Greenland whale, which proved to be even more valuable than the Biscay species. The huge mouth in these two whales has hanging from its sides within the lips a series of long bars or planks of wonderfully strong, elastic, horny substance—the "baleen" or "whalebone"—each plank being as much as eight or in rare cases twelve feet long. Following close on one another and having hairy edges, they act as strainers so as to separate the floating food of the whale from the water which rushes through its mouth as it swims. The whalebone is of great value commercially, as is also the fat or oil. A hundred years ago whalebone fetched only L25 a ton, now the same quantity fetches more than L1,500. The Rorquals, or "Finners," have smaller heads and mouths; their whalebone is so short as to be valueless, but they grow to even greater size than the Right whales and are found on our own coasts and all over the world. The Humpback whale is one of these "Finners," distinguished by its excessively long flippers and huge bulk.

The Biscay whale was the first of these great creatures to be hunted. The Basques began its capture as early as the ninth century. It was exterminated by them in the Bay of Biscay, and only saved from complete extinction elsewhere by the discovery of the more valuable Arctic or Greenland whale. The capture of the Greenland whale began in 1612; and in 200 years the unceasing pursuit of this species had driven it to the remote places of the Arctic Ocean. It is now so rare that it is not worth while to send a ship out for the purpose of hunting it, and it will probably never recover its numbers. An idea of its value and former abundance may be formed from the fact that between 1669 and 1778 it yielded to 1,400 Dutch vessels about 57,000 individuals, of which the baleen and oil produced a money value of four million pounds sterling. Of late years a single large Greenland whale would bring L900 for its whalebone and L300 for its oil. These two great Right whales having been practically exterminated, the merciless hunt has now been turned on to the wilder and less valuable Finback whales or Finners. In these days of steam and electric light the Arctic night is robbed of its terrors, and the whale chase goes on very fast. The shot harpoon was invented in 1870 by Sven Foyn, a Norwegian, and is the most deadly and extraordinary weapon ever devised by man for the pursuit of helpless animals. It is this invention (a commercial, not a scientific, discovery!) which has, in conjunction with swift steamships, rendered the destruction of whales a matter of ease and deadly certainty. It is this which is being used on the Irish as on the Scandinavian coast, resulting in the pollution of the air and water by the carcases of the slaughtered beasts from which the oil has been extracted. This revolting butchery, without foresight or intelligence, is carried on solely for the satisfaction of human greed, and apparently will be stopped only by the extinction of the yet remaining whales. In forty years in the middle of last century the whale fishery of the United States yielded 300,000 whales to 20,000 voyages, and a value of sixty-million pounds sterling in baleen and oil. It is calculated that in the thousand years during which man has hunted the great whales not less than a million individuals have been captured. Man's skill and capacity have now become such that he will soon have cleared the ocean of these wonderful creatures, since, like the bison, the whales cannot persist when harried and interfered with beyond a certain limited degree.

It appears that the curious musk ox, which now lives on the fringe of the Arctic circle, and in the glacial period existed in the Thames Valley, is doomed. There (as in similar instances in other lands), the comparatively harmless savage race of men (in this case the Eskimo), whose weapons did not enable them seriously to threaten the existence of the animals around them, have now obtained efficient firearms. The musk ox is consequently now between two lines of fire—that of the white hunter on the south, and of the Eskimo on the north.

From regions far remote from the Arctic complaints come of an even more reckless destruction of helpless animals. Perhaps our legislators may feel some personal concern in this case, since it is neither more nor less than the approaching extinction of the turtle, the true green turtle of City fame, to eat which at the invitation of City dignitaries is one of the few duties of a legislator. Both the green turtles and the tortoise-shell turtles are being destroyed indiscriminately on the coast of Florida and in many West Indian Islands by brutal, careless, "white" beach-combers and idlers. By proper care of the eggs and young the turtles could easily be increased enormously in number, and a regulated capture of them be made to yield a legitimate profit. But neither the United States Government nor our own take any steps to restrain promiscuous slaughter of the turtles which come to the shore in order to lay their eggs. Soon the City Fathers will have to do without the "green fat" and their wives without tortoise-shell combs. It will serve them right. Such destitution in these—and, be it noted, in many other matters—will deservedly fall upon those who ignorantly, wilfully, and contentedly neglect to take steps to understand and to control the withering blight created by modern man wherever he sets his foot.



CHAPTER XXVI

MORE ABOUT WHALES

The possibility of protecting whales from wanton slaughter by man is, no doubt, a matter open to discussion. Protection has, however, been accorded to one particular whale in an exceptional instance. Passenger steamers along the coast of New Zealand used to call at a station in a narrow inlet of the coast, called Pelorus Sound. A black whale, said to be of the kind known as Risso's Grampus, of about 14 ft. in length, was apparently a settled inhabitant of this channel, and used to follow the steamers and accompany them through the sound. He became famous and popular, and was known as "Pelorus Jack." He was always looked for and recognised by the sailors and passengers. Certain savagely destructive persons on one of these steamers—to the horror and disgust of the New Zealand world—made an attempt to shoot "Pelorus Jack." It is stated, and believed by sailors, that ill-luck consequently fell on that steamer. On its next voyage it was avoided by the whale, who had never failed to welcome friendly and non-aggressive steamships, and on a third voyage the steamer was wrecked. The feeling about "Pelorus Jack" was so strong that his Excellency the Governor of New Zealand, Lord Plunket, signed, on September 26th, 1904, an Order in Council, protecting "Pelorus Jack" by name for five years, and any person interfering with him was made liable to a fine of L100.

It appears that under the New Zealand Sea Fisheries Act of 1894 the Governor in Council is empowered to make regulations protecting any fish. Although zoologically not belonging to the class of fishes, whales are, technically and for all legal and commercial purposes "fishes," since they are "fished" and are the booty of "fisheries." I believe that no Governor, Council, or Secretary of State has power in the British Islands similar to that conferred on the Governor of New Zealand by a modern State which desires good and effective government. Such power is needed in all parts of the British Empire.

The whales, as compared with their dog-like ancestors, are modified to a more extreme degree and in more special ways than is the case in any other group of which we can trace the history over a similar period of development. This is connected with the complete change of conditions of life to which these mammals ("warm-blooded, air-breathing quadrupeds which suckle their young") have become adapted in passing from a terrestrial to a marine existence. Other mammalian ancestors have independently taken to a marine life and given rise to strange-looking adaptations, namely, the seals and also the Manatee and Dugong known as the Sirenians (so-called because they give rise to sailors' stories of mermaids and sirens), but these are far less changed, less modified than the whales. The whales have acquired a completely fish-like form. They frequently have a large back fin, and have lost the hind legs altogether. The horizontally spread flukes of the whale's tail have nothing to do with the hind legs, whereas the common seal's hind legs are tied together so as to form a sort of tail. In the bigger whales, sunk deep in the muscle and blubber, we find on each side well forward in the body (not near the tail) a pair of isolated, unattached bony pieces, which are the hip-bone and thigh-bone—all that remains of the hind limbs. The neck is so short that in many whales the seven neck-bones, or "vertebrae," are all fused into one solid piece not longer than a single ordinary vertebra, and showing six grooves marking off the seven vertebrae which have united into one.

The head is more strangely altered than any other part of the whale. The jaws are greatly elongated—so as to give a beak-like form in all—but this region is specially long and narrow in the "beaked whales" known to zoologists by the name Ziphius, in which it consists of a solid piece of ivory-like bone, which we find in a fossil state in the bone-bed of the Suffolk Crag. Farther back the bones of the face are suddenly widened in all whales and porpoises, and in many these bones grow up into enormous crests and ridges. The nostrils, instead of being placed, as in other animals, at the free end of the snout or beak, lie far back, so as to form the "blow-hole," which is near the middle of the head.

The circulation of the blood and the breathing of whales (including in that term the smaller kinds known as dolphins and porpoises) is still a matter which is not properly understood. When a Greenland whale is struck by the harpoon it dives vertically downward to a depth of 400 fathoms and more (nearly half a mile), and occasionally wounds the skin and bones of its snout by violently striking it on the sea-bottom. It remains below as long as forty minutes. Physiologists wish to know how the sudden compression of the air in the lungs in plunging to this depth and the equally sudden expansion of it in rising from such a depth is dealt with in the whale's economy, so as to prevent the absolutely deadly results which would ensue were any ordinary air-breathing animal subjected to such changes of pressure. Man can endure without suffering an increase of pressure of the gases in his body amounting to three or four times that to which he is accustomed, as, for instance, when working in the compressed air of "caissons." But the whale goes suddenly to a depth at which the pressure is eighty times that at the surface! Then, too, man (and other terrestrial animals), after being subjected (for instance, in a caisson) to a pressure of four times that which exists on the free surface of the earth, is liable to be killed by suddenly passing from that high pressure into the ordinary air. The gases dissolved in his blood expand like the gas in a bottle of soda-water when the cork is drawn, and the bubbles interfere with the circulation of the blood in the finer blood-vessels (of especial importance being those of the brain and spinal cord), and the serious illness and the death of workmen has frequently resulted from this cause. Accordingly, the men who work in such "compressed atmospheres" are now made to pass slowly through a series of three chambers, in each of which the pressure is diminished and brought nearer to that of the normal atmosphere. By spending twenty minutes in each chamber successively, the workman is gradually brought to the pressure of the outer world, and his blood prevented from "effervescing." But what must be the condition of the gases in the blood of a whale which suddenly rises from 400 fathoms to the surface? The whale suddenly goes, not from a pressure of four times the normal ("four atmospheres," as it is called), but from eighty times the normal, to the normal pressure.

Whales, and also seals, are provided with remarkable special networks of blood-vessels in various parts of the body (called "retia mirabilia" by the old anatomists,) and also with a thick layer of fat under the skin, the "blubber" (some feet deep in a large whale), full of blood-vessels. It has been suggested that these networks of blood-vessels are related in some way both to the power of keeping long (forty minutes!) under water without breathing, and also to the freedom of these marine monsters from the deadly effects of rapid passage from great to little gas-pressure. But it is only a suggestion; no one has shown how the networks can act so as to effect these results, and I am quite unable to say how they do so. Another suggestion worth considering is that the whale completely empties the gas out of its lungs by muscular compression of the body-wall before diving, so that there is no gas left in the body to be acted on by the increased pressure resulting from its sinking into deep water. I am unable to deal with this puzzle myself, and I have not been able to find any naturalist or physiologist who can throw light on the matter.

The toothed whales are nearer to the ancestral primitive whales than are the whalebone whales. The latter are the more peculiar, and specially adapted with their huge heads and mouths (a third the length of the whole animal in the Greenland whale), and their palisades of 350 whalebone planks, some 12 ft. long, on each side of the mouth. I may mention in parenthesis that, whilst whalebone has been largely superseded by light steel in the making of umbrellas and corsets, its value remains, or rather increases, on account of its being the only material for making certain kinds of large brushes which are used in cleaning machinery. The whalebone whales have, when first born, very minute teeth hidden in their jaws; they disappear. Some of the toothed whales have teeth only in the lower jaw (the cachalot), others (the beaked whales, Ziphius, etc.) have only one pair or two pairs of teeth. These are tusk-like, and placed in the lower jaw. Others (the dolphins and porpoises) have very numerous peg-like teeth in each jaw. Some of them feed on fish, pursuing the shoals of fish in parties or "schools."

A truly terrible toothed whale is the large porpoise called the killer (known to zoologists as Orca gladiator). He is the wolf of the sea, far more active and formidable than any shark, about 10 ft. long, and strangely marked in black, white, and yellow. He has jaws bigger than those of the largest Mugger crocodile, and a tremendous array of fang-like teeth. These killers hunt the Right (or whalebone) whales in all parts of the world, in parties of three to twelve. They hang on to the lips of their enormous "quarry," and once they get a hold, in twenty minutes tear it into pieces. Often they satisfy themselves with tearing out and devouring the gigantic tongue of their victim, leaving the carcase untouched.

The narwhal and the white whale, or Beluga, which furnishes "porpoise-hide" for boots and laces, are both caught in northern seas, and form a closely allied pair, similar to one another in shape and colour (the one white, the other grey), and of moderate size, about 12 ft. long. They both feed on cuttle-fish and minute shrimps, but the Beluga has many teeth and the narwhal (with the exception of some rudimentary ones) only a single pair, and these in the front of the upper jaw. In the female narwhal their pair of teeth remain permanently concealed in the jaw bone, and so does the right side one of the male. But the left side tooth of the male grows to an enormous size, projecting horizontally in front of the narwhal to a length of seven or eight feet. It is a powerful weapon, and is formed of ivory spirally grooved on the surface. The narwhal was called "the unicorn fish" or "Monoceras" in ancient times, and its spirally marked tooth was confused with the horn of the terrestrial unicorn—the rhinoceros. Very rarely the right tooth of the male narwhal grows to full size side by side with the left tooth. A specimen showing this double-toothed condition is in the Natural History Museum. A most curious fact, quite unexplained as yet, is that the spiral grooving on both the teeth turns in the same direction; in both it is like a spiral staircase in mounting which (starting from the base implanted in the jaw) you continually turn to the right. Now, in all other animal structures which have a spiral growth and are paired—one belonging to the right side of the animal, the other to the left, as, for instance, the spirally marked horns of antelopes and the more loosely coiled horns of sheep and cattle—one of the pair forms a right-handed and the other a left-handed spiral. They are "complementary"; one is the reflection, as in a mirror, of the other. Why the narwhal's tooth does not conform to this rule is a mystery.

It is a remarkable fact that only a few whales and porpoises eat fish or the flesh of other whales. The large toothed-whales, including the cachalot or sperm whale, and also the Ziphius-like beaked whales, live upon cuttle-fish. And it seems that they know where to hunt for this special article of diet and how to find it in quantity (probably at great depths in the ocean), which naturalists do not. Many new kinds of cuttle-fish have been discovered by examining the contents of the stomach of captured whales. The sperm whale feeds on monster squid and poulp such as we rarely, if ever, see alive or washed up on the shore. The hide of these cuttle-fish-eating whales and porpoises is scratched and scarred by the hooks attached to the suckers on the arms of the great cuttle-fish, and a test of the genuine character of ambergris which forms as a concretion in the intestine of the sperm-whale is that it contains fragments of the horny beaks and hooks of the cuttle-fish digested by the whale. The food of the whalebone whales consists of minute crustacea and of the little floating molluscs known as Clio borealis, as big as the last joint of one's little finger, which float by millions in the Arctic Ocean. The whalebone whales, after letting their huge mouths fill with the sea-water in which these creatures are floating, squeeze it out through the strainer formed by the whalebone palisade on each side—by raising the tongue and floor of the mouth. The water passes out through the strainer, and the nourishing morsels remain.

Some fossil jaws and skulls of whales from miocene and older tertiary strata are known which tend to connect the toothed whales with those mammals not modified for marine life. But the approach in that direction does not go very far. The extinct whales called Squalodon have tusk-like front teeth and molars which have the outline of a leaf with a coarsely "serrated" edge. The bones of the face are also, in them, more like those of an ordinary mammal than is the case with modern toothed whales. The snout is not so long, and the bones which form it are a little more like those of a fox's snout than are those of the dolphin's "beak." But on the whole it is astonishing how little we know of fossil whales. We have yet to discover ancestral forms possessing small hind legs, but whale-like in other features. Some day a lucky "fossil-hunter" will come upon the remains of a series of whale-ancestors probably of Eocene age, and we shall know the steps by which a quadruped was changed into a cetacean—just as we have recently learned the history of the development of elephants. We know even less about the ancestry of bats and the steps by which they acquired their wings than we do about the history of whales. These discoveries await future generations of men when "cuttings" and "pits" and quarries shall have been made in the rest of the earth's surface to the same extent as they have been in Europe and in parts of the American continent.



CHAPTER XXVII

MISCONCEPTIONS ABOUT SCIENCE

I submit, as the final chapter of this little volume of miscellaneous diversions, a few words intended to meet what has become a recurrent misrepresentation and absurdity for which the annual congress of the British Association for the Advancement of Science furnishes the opportunity. Glib writers in various journals regularly seize this occasion to pour forth their lamentations concerning the incapacity of "science" and the disappointment which they experience in finding that it does not do what it never professed to do. They deplore that those engaged in the making of that new knowledge of nature which we call "science" do not discover things which they never set out to discover or thought it possible to discover, although the glib gentlemen who write, with a false assumption of knowledge, pretend that these things are what the investigations of scientific inquirers are intended to ascertain. We read, at that season of the year, articles upon "What Scientists do not know" and "The Bankruptcy of Science," in which it is pretended that the purpose of science is to solve the mystery, or, as it has been called, the "riddle," of the universe, and it is pointed out, with something like malicious satisfaction, that, to judge by the proceedings of the congress of scientific investigators just concluded, we are no nearer a solution of that mystery than men were in the days of Aristotle: and it is added that false hopes have been raised, and that matters which were once considered settled have again passed into the melting-pot!

This kind of lamentation is not only (if I may use an expressive term) "twaddle," but is injurious misrepresentation, dangerous to the public welfare. The actual attitude of the investigators and makers of new knowledge of nature is stated in a few words which I wrote ten years ago: "The whole order of nature, including living and lifeless matter—from man to gas—is a network of mechanism, the main features and many details of which have been made more or less obvious to the wondering intelligence of mankind by the labour and ingenuity of scientific investigators. But no sane man has ever pretended, since science became a definite body of doctrine, that we know or ever can hope to know or conceive of the possibility of knowing, whence this mechanism has come, why it is there, whither it is going, and what there may or may not be beyond and beside it which our senses are incapable of appreciating. These things are not 'explained' by science and never can be."

So much for those who reproach science with the non-fulfilment of their own unwarranted and perfectly gratuitous expectations.

When, however, having created in their readers' minds an unreasonable sense of failure and a mistrust of science, such writers go on to make use of the want of confidence thus produced, in order to throw doubt upon the real conquests of science—the new knowledge actually made and established by the investigators of the last century—it becomes necessary to say a little more. The public is told by these false witnesses that science has "dogmas," and that men of science are less satisfied than they were with the "dogmas" of the last century. Science has no dogmas; all its conclusions are open to revision by experiment and demonstration, and are continually so revised. But science takes no heed of empty assertion unaccompanied by evidence which can be weighed and measured. "Nullius in verba" is the motto of one of the most famous Societies for the promotion of the knowledge of nature—the Royal Society of London.

It is especially in the area of biology—the knowledge of living things—that the enemies of science make their most audacious attempts to discredit well-ascertained facts and conclusions. They tell their readers that those greater problems of the science (as they erroneously term them), such as the nature of variation among individuals, the laws of heredity, the nature of growth and reproduction, the peculiarities of sex, the characteristics of habits, instinct, and intelligence, and the meaning of life itself, have advanced very little beyond the standpoint of the first and greatest biologist, Aristotle. This statement is vague and indefinite; the conclusion which it suggests is absolutely untrue. Aristotle knew next to nothing about the mechanism of the processes in living things above cited. At the present day we know an enormous amount about it in detail. But when men of science are told that they do not know the "nature" of this and the "meaning" of that, they frankly admit that they do not know the real "nature" (for the expression is capable of endless variety of significance) of anything nor the real "meaning" not only of life, but of the existence of the universe, and they say, moreover, that they have no intention or expectation of knowing the ultimate "nature" or the ultimate "meaning" (in a philosophical sense) of any such things. These are not problems of science—and it is misleading and injurious to pretend that they are.

I recently read an essay in which the writer is good enough to say that, owing to the work of Darwin, the fact that the differences which we see between organisms have been reached by a gradual evolution, is not now disputed. That, at any rate, seems to be a solid achievement. But he went on to declare that when we inquire by what method this evolution was brought about biologists can return no answer. That appears to me to be a most extraordinary perversion of the truth. The reason why the gradual evolution of the various kinds of organisms is not now disputed is that Darwin showed the method by which that evolution can and must be brought about. So far from "returning no answer," Darwin and succeeding generations of biologists do return a very full answer to the question, "By what method has organic evolution been brought about?" Our misleading writer proceeds as follows: "The Darwinian theory of natural selection acting on minute differences is generally considered nowadays to be inadequate, but no alternative theory has taken its place." This is an entirely erroneous statement. Though Darwin held that natural selection acted most widely and largely on minute differences, he did not suppose that its operation was confined to them, and he considered and gave importance to a number of other characteristics of organisms which have an important part in the process of organic evolution. The assertion that the theory of natural selection as left by Darwin "is now generally held to be inadequate" is fallacious. Darwin's conclusions on this matter are generally held to be essentially true. It is obvious that his argument is capable of further elaboration and development by additional knowledge, and always was regarded as being so by its author and by every other competent person. But that is a very different thing from holding Darwin's theory of natural selection to be "inadequate." It is adequate, because it furnishes the foundation on which we build, and it is so solid, complete and far-reaching that what has been added since Darwin's death is very small by comparison with his original structure.

Lastly, we are told by the anonymous writer already quoted that at the present time discussion is chiefly concentrated on the question as to whether life is dependent only on the physical and chemical properties of the living substance, protoplasm, or whether there is at work an independent vital principle which sharply separates living from non-living matter! And the obvious and common-place conclusion is announced that "the ultimate problems of biology are as inscrutable as of old." All ultimate problems are, I admit, inscrutable. It is, on the other hand, the business, and has been the glory and triumph, of science, to examine and solve problems which are scrutable! It is certainly not the case that, at the present time, discussion is concentrated on the question of the existence of a vital principle. There is absolutely no discussion in progress on the subject. No one even knows or attempts to state what is meant by "a vital principle." It is a phrase which belongs to "the dead past," when men of science had not discovered that you get no nearer to understanding a difficult subject by inventing a name to cover your ignorance. Thirty-five years ago the word "vitality" was used as some few philosophising writers are now using the term "vital principle." Huxley at that time attacked the views of Dr. Lionel Beale, who called in the aid of a mystical "principle," which he named "vitality," in order to "account for" some of the remarkable properties of protoplasm. As Huxley pointed out, this supposed principle "accounted for" nothing, since it was merely a name for the phenomena for which it was supposed to account. Huxley pointed out that many chemical compounds have remarkable properties—as assuredly have the chemical compounds which are present in protoplasm—but men of science have not found it to help them in investigating the mechanism of those properties to ascribe them to mystical intangible "principles" differing from the agencies at work in other less exceptional substances.

Thus, for instance, water, though a very common and abundant chemical compound formed by the union of two chemical elements, hydrogen and oxygen, which, at the temperature and pressure of the earth's surface, are gaseous, offers many strange properties to our consideration not shared by other compounds of gaseous elements. For instance, hydrogen, when it combines with gaseous elements other than oxygen, does not form a compound which is liquid at the temperature and pressure of the earth's surface. Its combinations with nitrogen, with chlorine, with fluorine, and even some with the solid element carbon, are under those conditions gaseous. What a special character, therefore, has water! Moreover, water, though a liquid, yet behaves in a most peculiar way when either cooled below ordinary temperatures or heated above them. It becomes solid when cooled, but expands at the same time, so that it is less dense when solid than when liquid—a most unusual proceeding! And when heated it is converted into vapour, but with a loss or "making latent" of heat, which, like its behaviour when solidifying, indicates that water is endowed with a very peculiar structure or mechanism in the putting together of its molecules. We might call these combined peculiarities of water "aquosity," and as we certainly cannot say why water should possess the lot of them, whilst other compounds of either hydrogen or of oxygen, or, in fact, of any other elements, do not possess this combination, we might say that their presence is due to "the aqueous principle," or "aquosity," which enters into water when it is formed, but does not exist in other natural bodies, and, indeed, "sharply separates aqueous from non-aqueous matter."

Happily, though such a view would have been considered high philosophy 200 years ago, no one is deluded at the present day into the belief that by calling the remarkable properties of water "aquosity" you have added anything to our knowledge of them. Yet those who invoke "a vital principle" or "vitality" in connection with protoplasm should, if they were consistent, apply their method to the mystery of water. Let us see how it would run. Though we may (the "vitalists" or "aquosists" would say) experiment with water, determine exactly the temperature and pressure at which these remarkable phenomena are exhibited, though we may determine its surface tension and its crystalline form, and even though we may weigh exactly the proportion of hydrogen to oxygen in its composition, yet when we look at a drop of water, there it is, a wonder of wonders, endowed with "aquosity," the ultimate nature of which is as inscrutable now as it was to Aristotle! It is perfectly true (we concede to the "aquosists") that the properties of water are not accounted for by science; that is to say that, though we can imagine the molecular and atomic mechanism necessary for their exhibition, we cannot offer any suggestion as to how it is that that particular mechanism is present in the chemical compound which the chemist denotes as H_{2}O, and is not present in other compounds, still less can we say "why" these remarkable properties are present—that is to say, for what purpose, although we know that if they were not present the whole history and economy of our globe would be utterly different from what it is. Nevertheless, in spite of their ignorance about the real nature of water, men of science do not invent an "aqueous principle" or "aquosity" with the notion of "explaining" water. And I have yet to hear of any duly trained and qualified biologist who is prepared at the present moment to maintain the existence of a "vital principle," or of a force to be called "vitality," supposed to be something different in character and quality from the recognised physical forces, and having its existence alongside, yet apart from, the manifestations of those forces.

Lord Justice Fletcher Moulton recently said: "The advance in science takes the workers in science more and more beyond the ken of the ordinary public, and their work grows to be a little understood and much misunderstood; and I have felt that, as in many other cases, the need would come for interpreters between those who are carrying on scientific research and the public, in order to explain and justify their work." Probably everyone will agree with the Lord Justice: but what are we to say of those responsible owners of great journals who not only abstain from providing such interpretation but allow anonymous and incompetent writers to mislead the public? Is the literary critic of a prosperous journal employed to write the City article?

There has been a repetition this year (1912) of the usual misrepresentation on the occasion of the meeting of the British Association. The President, Professor Schaefer, had let it be known that his address would be concerned with the chemistry of living processes, the gradual passage of chemical combinations into the condition which we call "living," and the possibility of bringing about this passage in the chemical laboratory without the use of materials already elaborated by previously existing "living" material. The announcement was immediately made in some "newspapers" that "startling revelations" were to be made by the President, that he was "to throw a bomb-shell" into the camp, etc. He did nothing of the kind. He gave an admirable and clear statement of the progress during recent years towards the realisation of the construction in the laboratory by chemical methods of the complex chemical combination which exhibits those "activities"—essentially movements, unions, disruptions and re-unions of extremely minute particles—which we call "living." The conclusion that such a gradual building up has taken place in past ages of the history of our earth was formulated more than forty years ago by Spencer, Tyndall, Huxley, Haeckel, and others, and has not been seriously attacked in the interval, but, on the contrary, generally accepted as a legitimate inference from the facts ascertained and the theory of the evolution or gradual development of what we call the material universe.

Professor Schaefer expressed the opinion, anticipated and shared by many other investigators, that the progress of chemical experiment renders it probable that further steps, culminating in the successful construction of "living" matter in the laboratory, are not beset by any insurmountable obstacles and will sooner or later be accomplished. There was no "bomb-shell" in this statement, and no excitement as its result among scientific workers nor amongst those who do not neglect to study the writings of the "interpreters" desired by Lord Justice Moulton. There are still some such interpreters carrying on the work of Huxley and of Tyndall, those great interpreters whose writings should be studied and treasured as classics.

The most interesting result of the attempt to treat the discussions at Dundee as a newspaper "sensation," comparable to the reports relating to motor-car bandits or the pronouncements of political factions, has been its complete failure. Serious thinkers of all schools seem to have adjusted themselves to the more modern way of regarding natural processes even when these relate to matters of such age-long interest to mankind as the inception of "living" organisms and of conscious humanity itself. There are fewer now than there were forty years ago who insist on the older barbaric "explanations" of these marvels. Few indeed venture to assert the existence of "spirits"—ghostly essences of various grades and capacities which enter the bodies of living things and escape from them like so much gas when they die.[10] The vegetable soul, the animal soul and the human soul are no longer imagined and described to us as definite "things" supposed to "explain" the complex processes which go on respectively in plants, animals and men.

Seventy years ago the facts which were known as to that changing state of material substances which we describe by the words "hot" and "cold," were held to be "explained" by the existence of a ghostly thing called "caloric," which was believed to enter various bodies and make them hot and then to escape from them and so make them cold. Primitive man multiplied such ways of explaining each and every process going on in the world around him and in himself. Mere words or names lost their first simple signification and acquired permanent association with imaginary spirits, demons, and haunting intangible ghosts, by reference to which our ancestors in their earliest "reasoning" explained to their own satisfaction the strange and sudden events fraught to them with the daily experience of pain or pleasure. The whole world was held by them to be "bewitched," and it was only by slow and painful steps that some knowledge of the persistent order of Nature was obtained, whilst the phantastic imagery which had served in its place, bit by bit disappeared. "Caloric" was a late lingerer, and was only got rid of when what had been so called was shown to be a vibration of particles—a mode or kind of motion—a "state," and not a mysterious fluid existing as a thing in itself.

Just as "caloric" no longer serves and is no longer possible as the supposed "explanation" of the behaviour of bodies in the hot or the cold state, so we no longer require the supposition of "spirits" of one kind or another as "explanations" of the living state of those products of our mother earth which are called plants, animals and men. In neither case do such "spirits" really "explain" the state in question; they are only names for the activity which it was imagined that they served to explain. These states or affections of matter remain as wonderful and important to us as they were before. But by giving up the prehistoric notions about them which have been handed on until the present day we can think of them in a more satisfactory way—a way which avoids the multiplication of unnecessary imaginary agencies and the conception of an intermittent and hesitating Creative Power, and substitutes for it the operation of continuous orderly and preordained forces.

It is true that we can neither ascertain nor imagine either the beginning or the end of the orderly process which we discover in operation to-day. We can trace it back by well-established inference into a remote past, but a beginning of it is not within the possibilities of human thought. We can, with reasonable probability of being correct, foretell the changes and developments which time will bring in many combinations and dispositions which are the manifestations of that process at this moment of time, but we cannot even think of a cessation of that process.

Should we ask, "Why does this process exist?" there is no answer. Nature does not reply; an awful silence meets our inquiry. The reproach is often urged against science—the knowledge of the order of nature—that it does not tell us "why we are here." Man inevitably desires to know why he is here; but "science," as that word is now understood, does not profess or even seek to answer that question, although the false hope has been raised in ignorant minds, sometimes by knavery, sometimes by honest delusion, that it could do so. By knowledge of nature mankind can escape much suffering and gain the highest happiness, but that is all that we can hope for from it. We shall never satisfy our curiosity; we shall never know in the same way as we know the order of nature, why—to what end, for what purpose—that order and not another order exists.

It is very generally supposed that it is the business and profession of science "to explain" things—that is to say, to show how this or that must and does come about in consequence of the operation of the great general properties of matter, known as the "laws" of chemistry and physics. This is true enough, but it is equally the work of science to assert that of many things for which mankind demands "an explanation," there is no explanation. It is further the work and the service of science to destroy and to remove from men's minds the baseless and pretended "explanations" which are no explanations but causes of error, blindness, and suffering.

Science, the destroyer of "explanations," is the purifier of the human mind, its cleanser from the crippling infection of prehistoric error and from domination by the terrifying nightmares of our half-animal ancestry.

Finally, in reference to the very ancient attempt to "explain" life and consciousness by the assertion that they are due to "spirits" which enter the bodies of animals and men, I must caution the reader against supposing that—for those who do not accept the belief that such spirits exist—the gravity and mystery of the manifestations of life and consciousness are in any way lessened. Those who reject the belief in "spirits" do not in consequence reject the ethical and moral doctrines which have too long been rendered "suspect" by the shadow cast over them by ancient superstition. The disappearance of that shadow will reveal friends where enemies were supposed to be entrenched.

At the meeting of the British Association in 1879 I delivered an address on "Degeneration: a Chapter in Darwinism." In the printed version of that address, published in the same year, there are some statements bearing on the matter above discussed which I reproduce here, since I can still make them with conviction.

"Assuredly it cannot lower our conception of man's dignity if we have to regard him as 'the flower of all the ages' bursting from the great stream of life which has flowed on through countless epochs with one increasing purpose, rather than as an isolated miraculous being, put together abnormally from elemental clay, and cut off by such portentous origin from his fellow animals and from that gracious nature to whom he yearns with filial instinct, knowing her, in spite of fables, to be his dear mother."