Professor Elias Metschnikoff was busy, when I saw him at the Institut Pasteur in Paris last September, with an experimental investigation of “appendicitis.” He finds that chimpanzees can exhibit this disease, and he is led by experiments on those animals to believe that a gas-producing micro-organism—the bacillus aërogenicus—already known as occurring in the human intestine—is especially active in exciting the disease. Parasitic worms or other foreign bodies must first wound the delicate lining of the appendix before the virulent gas-forming bacillus can penetrate and start inflammation and abscess. Metschnikoff was also investigating a disease of tropical regions, known as “the Yaws.” Most people would imagine that this name refers to a disease like the gapes, but it is quite different, being an ulceration of the skin caused by a spirillum.
Spirilla—corkscrew-like threads of excessive minuteness—are parasitic organisms, like bacteria, bacilli, and micrococci. They are of different kinds—some harmless, some deadly. One is common in the mouth of the healthiest of us—another causes one of our most terrible diseases. They can be distinguished by the microscope, though much alike. What microscopists call “dark-ground illumination”—that is, illumination by horizontal rays of light, obtained by a prism attached below the glass slip on which the object is placed for examination with the microscope, has been found at the Institut Pasteur to be a very ready way of showing the spirilla in fresh blood or sputum. The spirilla are alive, and are seen when highly magnified, shooting rapidly across the field of view with a corkscrew action, like brilliant silver threads. The detection of the microbe which causes an infective disease, is often the first step to the control of the disease, or to knowledge which enables man to avoid the disease altogether. Some striking examples of this have occurred of late years.
5. The Sea Serpent
The sea-serpent rarely puts in an appearance now, though a Cornish “manifestation” was reported last year. A recent account of a strange marine monster, declared by some to be, of course, the sea-serpent, seen but to disappear, was that given by Lord Crawford’s companions two years ago. In that case, and in others in which a huge fin-like structure, supported by fin-rays, has been seen projecting from the mysterious animal, it is not improbable that what was seen was a large seal of the “eared” kind, raising one of its long, webbed hind-feet from the water, a trick which some of them are known to have. Other reputed sea-serpents have been, in reality, a school of porpoises, or a line-like flight of sea-birds, or a mass of seaweed, or a whale in association with one or other of these—or, again, a real marine snake 5ft. long (such are well known and very poisonous), or a ribbon-fish 12ft. long. There is “no reason why there should not be” a huge and seldom-seen kind of animal living in the sea—like a serpent in appearance. No one can say, as the result of observation, that there is not, since no one has thoroughly explored the dark, unfathomed depths of ocean. Yet we gain very little when we have admitted our ignorance, and agreed that there is no reason why something should not be. The real question is, “Does the thing in question exist?” not “Could it possibly exist?” Does the great sea-serpent exist? The answer to that is, There is not much evidence to show that it does. Most persons who have looked into the matter would be willing to bet 100,000 to 1 against its being captured, dead or alive, and brought before the Royal Society within ten years’ time. Unless it be so captured and “tabled” it matters very little whether it exists or not. It must be “discovered” in order to become really interesting.
6. Giraffes and the Okapi
The baby giraffe at the gardens in the Regent’s Park is a most interesting and beautiful creature. In that respect she only resembles on a small scale her grown-up relatives. Next to elephants, giraffes take precedence for strangeness, beauty, and imposing size. Certainly they have done so with me ever since I turned one Sunday afternoon long ago from the great novelty of the day, the first hippopotamus sent from Egypt, round whom the world of fashion was crowding, and gazed into the beautiful eyes that hung over me, supported by a gracefully-curving neck. My tender regard for the beautiful creature was not shaken even when I felt a sudden jerk to the elastic band passing under my chin and saw my new Leghorn straw hat, with its ornamental bunch of Egyptian wheat and broad pink ribbon, disappear between the lips of the beauty. A slow right and left movement of the jaw followed, accompanied by a tranquil kindly look suggestive of a desire for more. That was one of the old stock of Regent’s Park giraffes, who bred freely at the gardens and made money for the society. They died out thirty years ago or more. From time to time since then there have been one or two mis-shapen giraffes in London, but they did not eat children’s hats nor produce young of their own. A new dynasty of Kordofan giraffes has now arrived, and a better spirit prevails.
The most interesting thing about the giraffe is the okapi. The remark sounds absurd, but it is true. The okapi is the new animal from the Congo forest of Central Africa, discovered in 1901 by Sir Harry Johnston. It is as big as a very large stag, has a neck like a deer, and is striped on the haunches and legs, not spotted as is the giraffe. Yet its teeth and its horns prove it to be a close ally, not of deer, but of the giraffe. Any points of agreement between giraffes and the okapi are, therefore, important. I have examined the baby giraffe at the Zoo, and find that she has stripe-like bands of hair on the face and on other parts of the head. Both her father and mother are from Kordofan, and have some six or seven strongly-marked bands of dark hair over the eyes and on the muzzle. It is important to note any colour-striping in the giraffe’s skin, since the giraffe’s colour-markings are mostly in the form of great spots, whilst the okapi is only marked by stripes or bands something like those of a zebra, but confined to the haunches and the legs, the rest of the body being dark brown. The tendency to develop colour stripes in the giraffe is important, since it shows us that the stripes do not separate the okapi absolutely from the camelopard; they are a common possession or possibility of the two animals. It was my examination of a half-brother of the little giraffe now alive at the Gardens which led to the discovery of striping on the head and face of giraffes. The mother in that case had died before the birth of her young one, and the dead calf was given to me by the secretary of the Zoological Society. Sixty-eight years ago Sir Richard (then Professor) Owen received a new-born giraffe from the Gardens, and reported on it to the Zoological Society. No one had examined one since that date; none were obtainable from the Zoo, and I could get none from African travellers and sportsmen, in spite of urgent requests. I was accordingly greatly pleased to secure one from the London Gardens. A great peculiarity of the young giraffe is that it is born with a pair of well-grown horns, nearly an inch long, and covered with coarse black hair. No other horn-bearing mammal—no antelope, buffalo, ox, sheep, goat, stag, or other deer—is born with horns, so far as we know, and we know a good many of these animals well. Before birth the young giraffe’s horns are flat from back to front, and quite soft and flexible. They can be pressed backwards, so as to be made to lie flat on the head. Directly after birth a hard, bony deposit commences inside the horn, and after some years’ growth it becomes firmly fused to the skull. But the hard bony core never breaks through the hairy skin which covers it. The bony core of the okapi’s pair of horns, on the contrary, does “cut” or break through the skin, exposing a sharp, hard point, a quarter of an inch in length. In the deer tribe, as everyone knows, the point of the bony horn-core spreads out as a large, branching growth from which all covering is shed, and forms the “antler.” The deer tribe shed the antlers every year from the top of the horn-core, and grow a new and larger pair to take the place of the old ones. Moreover, in them the horn-core itself is a stem-like upgrowth of the bone of the skull (of the frontal bone). In the okapi and the giraffe the horn-core is a separate bone, free at first and fusing with the skull only when the adult condition is reached. The little antlers or bare-points of the okapi’s horn-cones or cores seem to be shed in segments as growth goes on, and are only minute things compared with the antlers of stags. The giraffe’s horns, on the other hand, always remain covered by skin and hair and have a broad, rounded top, not a sharp point.
The real clinching feature in the okapi and giraffe which decides at once their close affinity to one another is found in the outer tooth on each side of the group of eight teeth placed in the front of the lower jaw. In both this particular tooth has a broad, chisel-like crown, divided into two portions by a deep vertical slit. None of the other ungulate or hoofed animals have this very curious shape of tooth. It is a sort of family “mark” or “feature” in okapis and giraffes, as may be seen in specimens shown in the gallery of the Natural History Museum, where we have now no less than three fine, well-stuffed okapis and several varieties of giraffe.
7. The Great Geologists of Last Century
The centenary of the foundation of the Geological Society of London, celebrated last year, was a genuine festival in the scientific world. Though geology had its teachers and searchers before 1807 (Hutton and Werner, and the Neptunian and Plutonic schools, with their theories as to the origin of rocks on the one hand by marine deposit, or on the other by igneous agency, flourished before that date), yet it is true that the adequate conception of the problems of geology and the proper use of accurate observations and of judicious theory based on those observations, in relation to the problems of geology, coincided with the foundation of the society. It was not the first “special” scientific society founded in London; there was already the Linnean Society (founded in 1788) for the cultivation of zoology and botany. Yet it incurred the displeasure of the worthy president of the Royal Society, Sir Joseph Banks, who at first joined it, and then withdrew from it, when, in 1809, it ceased to be a dining-club, meeting at a London tavern, and acquired rooms of its own at No. 4, Garden-court, Temple. Apparently there was a notion in those days that the “Royal Society for the promotion of Natural Knowledge,” founded in 1662, should exercise a sort of paternal control over any society formed for the special promotion of one branch of science. Independence has, however, been found to be the healthiest condition, and we now have not only the Linnean and the Geological, but the Zoological, the Chemical, and the Physical Societies, vigorous and important corporations, publishing their “Transactions,” and meeting for discussion. There is, it is true, a danger that the Royal Society may be left eventually, owing to these independent establishments, in the sole possession and control of the doctors and the engineers. It is a curious fact that the word “physiology,” which in Cicero’s time (he says “Physiologia naturæ ratio”) and in the Middle Ages meant what we now call “natural history,” has been abandoned by other sciences, and appropriated by the medical men. In England, but not abroad, the doctors have even usurped the words “physician” and “physic.” In France, on the contrary, and more correctly, Lord Rayleigh and Sir William Crooks are called distinguished “physicians,” and the theory of the luminiferous ether is “physic.”