MYSTERY OF CANCER.

Manawatu Herald, Volume XXXIII, Issue 993, 18 May 1911, Page 4

MYSTERY OF CANCER.

GERM LOCATED IN PLANT LIFE. MAY BE COMMUNICABLE TOMAN. Is cancer a germ disease, and has the germ of cancer been discovered at last ? The experts of the United States Department of Agriculture announce that they have found a genuine cancer of the plant, and they have found the germ or bacterium that causes that cancer.

They declare officially that the cancer they have discovered in plants is very similar, perhaps identical, with that which afflicts human beings. In any case, it is declared to be a growth of exactly the same type. Now, this is of vast importance to humanity. Cancer, the greatest plague that afflicts humanity, is still an insoluble problem to science. Neither its nature nor its cure is understood. It is obvious that the first step towards a cure of a disease, is to understand its original cause, its nature. When that is done, the way is cleared to prepare a remedy according to certain well-approved principles. No one has been able to say just what causes human cancer. No one has been able to prove whether it is caused by a germ or not, although advanced medical investigators have been inclined to say that it is not. The favourite theory is that it is the result of misplaced body cells, which, in a wrong environment, undergo abnormal growth and destroy the whole organism. A vast mass of new facts has been gathered lately concerning cancer, but no certain conclusion has yet been drawn from them. The theory just mentioned is partly based upon these facts, but even its supporters admit that it is not fully demonstrated.

MEDICAL ADVANCES. Medical science has been concentrated upon cancer because it is now recognised as the greatest menace to mankind. It is even feared that it may be the means of destroying all human life on eartu. It is true that it is at present second to tuberculosis as a cause of death, but, nevertheless, it is a greater menace. Tuberculosis is on the decrease. Cancer is on the increase. We know how to cure tuberculosis. We do not know how to cure cancer. Men can eradicate consumption if they give the necessary time and money to the object. They cannot thus conquer cancer with their present knowledge, even if they should devote their whole efforts to it. Research has established the regions of the human body in man and woman which are most subject to cancer. This is important, because it warns people where to expect the disease. Research has shown that cancer can be transplanted from man to animals and from one animal to another. It has shown that while cancer is not strictly hereditary, certain families are more subject to the disease than others. It has shown that practically all living animals are subject to the disease. Most of the investigators have decided that cancer is not a germ disease, because although they have found many germs in the tumors, they have not found one that is invariably present. The difficulty of finding the specific germ, by the way, is partly explained by the parasite they have found in plant cancer which is present in very small quantities and very hard to isolate. Another very recent discoveryconcerning cancer was that fish suffered from it to a remarkable extent. It was then suggested that the fish might be the source of all cancer in man. probable source of vaccine. At last the origin has been traced to the plant world, still further down in the scale of life. This discovery, it is expected, may lead to the isolation ot the germ in human cancer. That will point the way to preparing a cure for the disease according to wellknown principles. The remedy will probably take the form of a vaccine or an anti-toxin prepared from the germ.

The germ discovered by the Department of Agriculture is a bacterium and has been isolated from the daisy. It is the cause of a plant disease, known as “ crown gall,” which has long been regarded as very mysterious. The malady in question attacks many kinds of plants, being conspicuously an enemy of grape vines. It forms tumors closely resembling malignant growths which in human beings and lower animals are known as cancers. AN ABNORMAL GROWTH.

It appears, in a word, that plant cancer —variously known as “crown gall,” “black knot,” “root tumor,” and by various other names—corresponds in all important respects to cancer in men and animals. It is called “crown gall” because of the fact that it most commonly assails the crown, or top part, of the root, just where the plant begins to develop from the latter. Thus, for example, the crown of the

common garden beet is especially liable to develop such an excrescence. The disease may, however, and oiten does, appear on the stems of the grape vine or other plant, some distance above ground. Up to the present time no germ has been identified as accountable for cancer in human beings and animals. Un this account many physiologists have been inclined to believe that there was no specific germ. But the unsatisfactory character of th.s argument is shown by the fact that up to the present time it might have been applied equally well to plant cancer. In truth, for many years scientific investigators have been making the utmost efforts to discover the microbe or “crown gall,” though without success. One remarkable thing about the disease is its readiness to assail plants of many different species and genera. In this point, however, it is not unlike the cancer of human beings, to which most other animals seem to be more or less liable, even including fishes. Many kinds of fruits and vegetables are attacked by the gall malady, which produces in all of them much the same symptoms.

THE ELUSIVE MICROBE. There was plenty of material to work upon, but the germ so earnestly sought, persistently eluded recognition and Identification. It is now known that the reason why was simply that the responsible microbe is not at all abundant in the affected tissues, and is sometimes even rare. It is always hard to see, and apparently it multiplies only inside of the living cells, which are stimulated by its presence to divide with great rapidity. Such division signifies very rapid multiplication, resulting in an overgrowth of a morbid character —in other words, a tumor. A tumor of this kind is of the same malignant character as a cancer in a human being. No cure for it has hitherto been known, and, accordingly, the principal recommendation made to grape-growers, for instance, has been that they plant vines of gallresistant varieties ; in other words, varieties which have shown themselves least liable to the disease. Among human beings there are some families which are exceptionally liable to cancer, the diseases appearing in generation after generation, while other families are seemingly immune. With plants, it must be supposed, it is much the same way. CAPTURED !

Now, investigation ot this interesting subject went on for quite a number ot years without any definite results until, in 1907, Dr. Erwin F. Smith and Dr. C. O. Townsend, pathologists in the Department of Agriculture, gave notice of the discovery of a certain bacterium which had been conclusively proved to be responsible tor tumors of a cancerous description ou the roots of daisies. They had succeeded in isolating this germ, to which they gave the name of Bacterium tumefaciens.

Having once got hold of the organism, they bred it on gelatin, thereby obtaining it in unlimited quantities for experimental purposes. They used it for inoculating healthy plants of many different kinds, such as tobacco, tomato, sugarbeet, hop and peach, and in every instance they produced galls ; in other words, cancers, at the point ol inoculation. Successful inoculations of grape vines were likewise made.

Nothing could be easier. The process was exceedingly simple. All that was necessary was to make a small wound, introduce a trifling quantity ot the disease “culture'’ and presently the growth started. In the same way, later on, tumors were produced ou plants of carnation, raspberry, apricot and apple. All of them were much alike, and one conclusion definitely drawn from the experiments was that the malady which had given so much trouble to growers of fruits and vegetables was always the same complaint, no matter what kind of plant it assailed. It was simply plant cancer every time.

It had already been ascertained that the disease was highly infectious. Previous experimenters had found that it could be communicated to a healthy plant by making a wound and binding thereupon a piece of fresh-cut tumor from an affected plant. The infection was even shown to be carried from one place to another in vineyards by surface irrigation; in other words, the germs were transported by water. Suggestion was made that insects conveyed it from diseased plants to healthy plants—a theory presumably correct enough, though as yet unproven.

But what was the nature of this germ ? Some experts were inclined to suppose that it was a microscopic fungus ; others that it was an animal organism of the kind known as a “plasmodium” —of the same breed as the malaria microbe. But now at last the matter is finally settled, and the Department of Agriculture presents the undoubted author of the mischief imprisoned in a “ culture tube.”