tacked. It is this increasing complexity of affairs which supports from the scientific side the dictum that the physician is to treat the patient rather than the disease for there is no longer a type disease to be recognized regularly. This brings us back to the original subject of etiology. A careful biological study of the many parasitisms of man and the higher animals brings out the fact that the highly specialized parasites have no obstacles to their activity, except one and that is immunity, either acquired or natural. As a result all host individuals pass through the disease early in life provided opportunity for invasion is given. The highly specialized diseases tend to become, in endemic localities, children's dis eases. In the case of many other diseases certain non-parasitic factors are necessary to start the disease or to check it, as the case may be. They are part of the mechanism of causation and represent necessary conditions. These necessary conditions may far outweigh the living agents in etiological significance. The relative importance of the living factors may be so low that their place may be taken by other living agents or even non-parasitic factors in the sequence leading to or continuing existing disease processes. This is probably true of certain diseases of intestinal origin. Such diseases are frequently described as due to different microbic agents in different localities because the endemic flora happens to be different. The relation between the factors of parasitism on the one hand and those of heredity, environment and the like on the other may be briefly summarized as follows: In the saprophytic or predatory type representing the so-called septic infections the other parasitic and non-parasitic factors are of great, even predominating importance in the production of disease. In the highly parasitic type they are of little, if any, importance unless it be hereditary characters brought out by the selective action of the parasites themselves upon the host species through many generations. Many gradations exist between these extremes and the relation of parasitic to extra-parasitic factors is different for the different grades. Moving parallel with the degree of adaptation and specialization and the development of more nearly perfect cycles by the parasites the mortality drops and the morbidity at first spreads and finally tends to decline in certain types of parasitism, provided always that other types of parasitism do not accidentally enter to modify and complicate the normal course. In tracing the various living agents through the body of the host we find that we do not know the details of any parasitism to our satisfaction. These details, of course, include also the non-parasitic factors or conditions essentially favoring or hindering the parasite in its sojourn in and its journey through the host tissues. It is perhaps needless to refer at length to the conditions which control the acquisition of such knowledge. The hope of finding some preventive or cure dictates the course of many workers. When something approaching this has been found the etiological significance of all the other factors bearing on the disease falls below the horizon for the time being. The importance of continuing the study of the disease persists however even for practical reasons, for the remedy or preventive may not prove to have the success anticipated. To induce men to fill the gaps of our knowledge seems quite as important as the pioneering for entirely new vistas or outlooks. Great discoveries are, as a rule, half-truths that must be brought into line by patient afterresearch. The filling of gaps may be necessary to stage the next great discovery. There is beyond the mere knowledge that gaps exist the difficulties of the problems involved to be considered. Are we prepared to solve them directly or must we rely on indirect approaches and on the solution of analogous problems to satisfy our etiological sense? Added to these difficulties inherent in some phases of the parasitic cycle, notably that phase which takes place within the host, is the fact that the various disease agents attacking the same species, man for instance, are so different from one another that we may safely consider them surviving types. It would seem that where two or more parasites follow the same route and multiply in the same tissues a certain competition tends to eliminate one or the other. If two closely related types exist they rarely multiply in the same host at the same time. Such competitive elimination would leave a divergent assortment of parasitic organisms and resulting diseases, none of which would be an exact copy of the other. In this case the working out of one cycle does not necessarily enable us to predict what another would be. They must each and all be studied individually. In this dilemma we may gain assistance from a study of parasitisms in those remote and isolated regions which have not yet been seeded by the white man's diseases, where the prevailing maladies may still be "pure lines," rather than mixtures and combinations. Another source of material are the many characteristic parasitisms of animal life, notably of the mammals and birds. Comparative pathology may furnish us with that information which experimental pathology finds it impossible to produce. Taking all the diseased and abnormal states due to living agents in man and the higher animals together, a series may be established which fills in many gaps and which may furnish the suggestions and clues needed to bring about a better insight into the dynamic relations between host and parasite. Only through the cooperation of comparative and experimental methods may we hope to gain enough general underlying concepts to explore with some show of rationality new diseases successfully. Since science is valued in proportion to its capacity to predict successfully certain events, medical science will be judged by the way it takes hold of a new phenomenon to determine its etiological antecedence. If, in the course of its development, it has failed to take cognizance of factors necessary to build the science into a consistent whole, it should retrace its steps and make up the deficiency. Parallel with the continued analysis of phenomena there should be another process going on to simplfy the complexity resulting from the former and to bring the results of scientific inquiry more or less within the reach of everyday life. What is needed is a synthesis of the many data resulting from analytic study of phenomena. Perhaps I can make myself clearer by using as an illustration some recent investigations. If we examine the various diseases in which the virus is conveyed by insects and arachnids, we shall find that many of the data pertaining to the dissemination of the virus had been accurately worked out before the mode of transmission was discovered. There was lacking, however, a something to harmonize and coordinate them. When the insect carrier was defined these various discrete, apparently unrelated data fell into line. Here was a synthesis which not only substantiated older observations but it enabled the scientist to use the deductive method to develop new inquiries and thereby lift the subject up to a higher level for further analysis. For some years we had known that a certain disease of young turkeys, due to the invasion of the tissues through the intestinal tract by a protozoan parasite, could be prevented by raising these birds away from older turkeys and common poultry and on soil uncontaminated by them. The explanation came through the discovery that a common worm of these species was needed to injure the mucous membrane and thereby open the way for the protozoan parasite. The nematode also accounted for certain disturbances in the application of the above rules in the rearing of these birds. It synthesized, in other words, the accumulated data. With the aid of these illustrations it is possible to understand, at least in part, what must have been the effect of the rapid discovery of various living agents in the eighties of the last century on the medical mind of the period. Many apparently unrelated data suddenly moved into line and assumed definite relations to one another. The discoveries pertaining to acquired resistance to disease involving the action of antitoxins, agglutinins, precipitins and the like have not had as yet the desired effect of synthesizing the conception of immunity, because they may be ac cessories rather than essential factors, all grouped around some more fundamental, unifying, still undefined phenomenon. THEOBALD SMITH DEPARTMENT OF ANIMAL PATHOLOGY THE FIRST APPEARANCE OF THE I HAVE recently published a paper1 under this title, naming one species Mastodon matthewi from the Lower Pliocene of Snake Creek, Nebraska, and another species Mastodon merriami from what I supposed to be the Middle Pliocene of Nevada, in honor of Dr. William D. Matthew and Dr. John C. Merriam, respectively. I have just learned from Dr. Merriam that Mastodon merriami is not, as I supposed, of Pliocene but of Middle Miocene age, which makes this species all the more important and interesting as the first to reach America. Dr. Merriam writes, June 24, 1921: The locality described by Mr. Hills, namely, that at which G. D. Matheson secured his material, is, however, in the Virgin Valley formation, which is of approximately middle Miocene age, not far from the zone of the Mascall of the John Day region. The opal mines are in the Virgin Valley formation and lie between the two main forks which unite to form Thousand Creek. These streams are Virgin Creek and Beek Creek. They unite on the west side of the great Rhyolite mass which separates the lower part of the Virgin Valley beds from the areas of the Thousand Creek formation lying to the east. The change in the age of Mastodon merriami suggested by the data given above will, I am sure, interest you greatly as this evidently brings the appearance of these Mastodons back to near middle Miocen. I am greatly surprised and interested by the Middle Miocene appearance of the true mastodons in America, if the above report by Dr. Merriam is correct, as I have no doubt it is. Middle Miocene age is, in fact, quite consistent with the structure of the superior canine tusks, which bear a broad enamel band on a 1 Amer. Mus. Novitates, No. 10, June 15, 1921. concave outer side, a fact that puzzled me greatly because Dr. Schlesinger describes the Lower Pliocene mastodons of Hungary as bearing an enamel band on a convex outer surface. We should expect the earlier mastodons to show just the difference in the curvature of their tusks which these two observations would indicate. It now seems that the true mastodons may be traced back to the species Palæomastodon beadnelli Andrews, living along an ancient river corresponding to the Nile, in company with a primitive long-jawed proboscidean to which Andrews and Beadnell gave the name Phiomia serridens in 1902. This was in Upper Eocene or Lower Oligocene times. In Lower Miocene times the true mastodons appear in North Africa and reappear in the Middle Miocene of France, although far less abundant than the contemporary species of long-jawed animals named Mastodon angustidens by Cuvier, which are descended from Phiomia. The rarity of the true mastodons is attributable to their strictly forest-living habits. They occur rarely in the Miocene and Lower Pliocene of France and Switzerland, also in Austria as recently described by Schlesinger of Vienna. If the Mastodon merriami of Nevada proves to be of Middle Miocene age, it will demonstrate that these true mastodons came to this country much earlier than we have been led to suppose. The earliest arrivals hitherto recorded in this country are the Mastodon brevidens and M. proavus of Cope, which hailed respectively from the Middle Miocene of Oregon and of Colorado. It is not yet positively known whether these two species are true mastodons or representatives of one of the other phyla. HENRY FAIRFIELD OSBORN AMERICAN MUSEUM OF NATURAL HISTORY, June 29, 1921 SCIENTIFIC EVENTS THE SCIENCE CLUB OF THE UNIVERSITY OF MISSISSIPPI DURING the academic year 1920-21, the Science Club of the University of Mississippi, composed of members of the science faculties, held seven meetings. The following papers were presented: Oct. 1920. Tabulated results of questionnaire circulated among students the previous year to ascertain student attitude toward marriage, by H. R. Hunt, Ph.D. Nov. 1920. Some phases of American archæology (lantern demonstration), by Calvin S. Brown, Sc.D. Dec. 1920. Intestinal intoxication as a bacteriological problem, by Paul R. Cannon, Ph.D. Jan. 1921. Tabulated results of physical examination of students, with discussion, by Byron L. Robinson, M.D. Feb. 1921. Petroleum, with particular reference to its presence in Mississippi (specimens demonstrated), by J. N. Swan, Ph.D. Mar. 1921. Influenza, case citations and brief review of literature, by Whitman Rowland, M.D. April 1921. Malaria, its incidence and control, by W. S. Leathers, M.D. Throughout the past year the club has extended the privilege of its meetings to advanced students, and with very gratifying results. C. F. DE GARIS, Secretary THE WORK OF THE ROCKEFELLER FOUN DATION A REVIEW of the work of the Rockefeller Foundation, issued by the president, Dr. George E. Vincent, summarizes as follows the activities of the Rockefeller Foundation, the International Health Board, the China Medical Board and the Division of Medical Education: Aided six medical schools in Canada. Gave a large sum to a medical training center in London. Appropriated 1,000,000 francs for the Queen Elisabeth Foundation for Medical Research in Belgium. Agreed to contribute toward the complete rebuilding of the medical school of the University of Brussels. Provided American medical journals and laboratory supplies for ten medical schools and medical libraries in five European countries. Continued to construct and maintain in Peking, China, a modern medical school with a pre-medical department. Aided thirty-one hospitals in China to increase their efficiency in the care of patients and in the further training of doctors and nurses. Supported the School of Hygiene and Public Health of the Johns Hopkins University. Contributed to the teaching of hygiene in the medical school at Sao Paulo, Brazil. Provided fellowships in public health and medical education for ninety-three individuals who represented thirteen different countries. Brought to the United States commissions of medical teachers and hygienists from England, Belgium and Czechoslovakia. Continued to support a campaign against yellow fever in South and Central America and in West Africa. Aided Government agencies in the control of malaria in ten states of the South. Prosecuted hookworm work in ten southern states and in eighteen foreign countries. Helped to expand anti-hookworm campaigns into more general health organizations in countries, states. and nations. Brought a wartime anti-tuberculosis work in France to the point where it could soon be left entirely in French hands. Assisted the Government of Czechoslovakia to reorganize its public health laboratory system. Rendered various services in organizing committees to study the training of nurses and of hospital superintendents, lent experts for conference and counsel, sent officers abroad to study conditions, etc. Brought to a close its participation in wartime emergency relief by giving $1,000,000 to the fund for European children. THE EXPOSITION OF CHEMICAL INDUSTRIES As has already been noted in SCIENCE, the Seventh National Exposition of Chemical Industries will be held at the Eighth Coast Artillery Armory, New York City, during the week of September 12. According to an announcement issued by the directors, the growth of the Chemical Exposition during the last seven years has been a barometer of the trend of public thought and interest in America's scientific achievements. Manufacturers, engineers, scientific men and students are drawn toward these remarkable displays from all corners of the country. It has therefore be come necessary to stage the 400 exhibits of this year's event in an exposition building of immense proportions, covering an area of five city blocks. As much of the program is carried out in speeches, lectures, and papers of value to the investigator along these lines, a special auditorium arranged according to the plan of a theater, and having a seating capacity equal to many such houses, will meet the needs of a quiet and comfortable lecture hall. It will offer an ideal place for the many symposiums that will be held during the week. These will take the nature of scientific discussions, practical talks, exchange of ideas, "get together" meetings, and motion pictures covering every industry, lent through the courtesy of the government, numerous companies and plants where these industrial reels have been filmed. Dr. Charles H. Herty, editor of the Journal of Industrial and Engineering Chemistry, is chairman of the advisory committee. Others on this board include Raymond F. Bacon, director, Mellon Institute; L. H. Baekeland, hon. professor chemical engineering, Columbia University; Henry B. Faber, consulting chemist; John F. Teeple, president, the Chemists Club; Bernard C. Hesse, chemist, General Chemical Co.; Acheson Smith, president, American Electrochemical Society; A. D. Little, president, Arthur D. Little, Inc.; William H. Nichols, chairman of the board, General Chemical Co.; H. C. Parmelee, editor, Chemical and Metallurgical Engineering; Fred W. Payne, co-manager of the exposition; R. P. Perry, vice-president, The Barrett Co.; Charles F. Roth, co-manager of the exposition; Edgar F. Smith, president, American Chemical Society; T. B. Wagner, vice-president, U. S. Food Products Corporation; David Wesson, president, American Institute of Chemical Engineers; and M. C. Whitaker, president, United States Industrial Chemical Company. The headquarters of the exposition are now located at 342 Madison Avenue, New York City. THE CHEMICAL MEETING IN NEW YORK CITY GOVERNOR MILLER will go on Labor Day to Niagara Falls to welcome officially the dele gates of the British Society of Chemical Industry, who will visit the United States to hold a joint meeting with the American Chemical Society. At the head of the overseas delegation will be Sir William J. Pope, president of the Society of Chemical Industry. Among other prominent members will be Dr. Louis A. Jordan, who was sent to aid the Italian government in the making of explosives; Dr. Frederick William Atack, whose principal work has been the chemistry of dyes; Dr. Andrew McWilliams, one of the best known steel metallurgists in Great Britain; and Dr. Andrew Smith, an explosives engineer of international reputation. Some of the eminent Canadian chemists will be: Dr. R. F. Ruttan, past president of the Canadian Section of the society; Dr. Milton L. Hersey, one of the founders and past chairman of the Canadian Section; and Dr. C. R. Hazen, chairman of the Montreal Section. According to the preliminary program of the American Chemical Society, made public today, registration begins at the Chemists Club, 52 East 41st Street, on Tuesday, September 6. The dinner of the Council will also be held at the club. The general meeting will convene at 10 o'clock on the following day at Columbia University, and at half past twelve o'clock the Society of Chemical Industry's luncheon to British and Canadian visitors will take place. There will be a reception and lawn party for the members of all societies concerned, to be held on the Campus of Columbia University, and in the evening a smoker will be held in the Waldorf-Astoria. A joint meeting of the American Chemical Society and of the Society of Chemical Industry of Great Britain has been arranged for four o'clock on Thursday afternoon and in the evening will be held a banquet at the Waldorf-Astoria. The various divisional and sectional meetings are scheduled at Columbia University. The sessions will conclude with a public meeting, at which the president, Dr. Edgar F. Smith, will deliver the annual address. The last day will be given to excursions to various chemical plants and other points of interest in the city. |