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Rh in the working of this plan is shown by the fact that the system, which originally included medicine, surgery, and pediatrics, was in 1920 extended so as to take in gynaecology and obstetrics. The system was also adopted in the main clinical branches. by the medical departments of Washington University (St. Louis), Yale University, Vanderbilt University, university of Chicago, and the university of Rochester.

China. Through a subsidiary board (the China Medical Board) the Rockefeller Foundation of New York has established in China a modern medical school. The Rockefeller Foundation has furnished funds amounting to 8,000,000 to build and equip the Pekin Union Medical College, and in addition it was in 1921 supporting the institution on the basis of a budget for the year amounting to $500,000. The institution furnishes two years of pre-medical work, and intended to develop a four-year medical course. In addition to the undergraduate training of Chinese physicians, it will provide graduate training, offers short courses for physicians in the field, and endeavours to extend in the Orient a popular knowledge of medicine and public health. The China Medical Board also aids four other medical schools in China carried on by other organizations.

Belgium. The university of Brussels had in 1921 planned a com- plete reorganization of its medical department. The city, the State, and the university cooperated in maturing plans for a modern teach- ing hospital, and new, well-equipped laboratories on a single site. Approximately 100,000,000 francs was needed to finance the enter- prise, of which 40, 000,000 was pledged by the Rockefeller Foundation.

(A. Fx.)

Canada. There were in Canada eight medical colleges in 1921 giving a complete course leading to the degree in medicine. In every case the college forms a part of a university, and most of them are to be found in the eastern provinces. In the West only one university (Manitoba) gives a complete medical course, though the university of Alberta offers the first three years of a six-year course, her students as a rule finishing their work in one of the eastern universities. During the years 1910-21 there was a steady advance in standards in the medical curriculum. The four-year course, which followed a minimum entrance requirement of Junior matric- ulation, was first increased to five years and later to six years in most of the schools. The five-year course was planned partly to meet the demand for increased instruction in the so-called pre- medical sciences and partly to give more time for the clinical branches. Where this course is in force the first year is devoted to biology, chemistry and physics, the second and third years to anatomy, physiology, histology and embryology, physiological chemistry, pharmacology, pathology and bacteriology, the fourth and fifth years practically to the clinical subjects, namely, medicine, surgery, obstetrics and gynaecology with their various special branches. The increase to six years gives more time to the clinical subjects, and in addition enables the Faculties of at least some of the schools to offer certain electives or options. This latter plan gives to the better-class student an opportunity to graduate with more than the minimum requirements for the degree of M.D. The six-year course is given in certain of the schools entirely within the medical department, although the curriculum includes certain courses to be taken in the other Faculties. Other schools plan to require two years as a pre-medical requirement to the four-year course. These two years may be taken in any of the standard universities and must include biology, chemistry and physics. At least one school was in 1921 planning to add to the four-year course a hospital year, which must be taken before graduation. In most of the medical schools the regular course in medicine leads to the degree of M.D. or to the degree of M.D.-C.M. One school gives the degree of M.B. at the close of the regular course, with the M.D. one year later on presenta- tion of a satisfactory thesis. The combined degrees of B.A.-M.D. or B.Sc.-M.D. may be obtained in practically all the schools in seven or eight years. A special degree of B.Sc. (Med.) may be obtained in t*o of the schools by a year of special work at any time after the third year of the regular course in medicine. (G. W. S.) MEDICAL ENTOMOLOGY. What used to be called com- prehensively "economic" entomology is now more conveniently divided into two distinct branches economic (see ECONOMIC ENTOMOLOGY) and medical. In its medical bearings the scope of entomology comprehends not insects only but arthropoda of every kind directly hurtful to health. Until about 1880 the fact that many arthropoda can bite and sting, and that some are troublesome parasites of man, was not thought important enough in medical practice to require special attention in their entomological aspect; but when in the last quarter of the igth century the startling announcement was made that one of the commonest diseases of the tropics is propagated by a bloodsuck- ing insect it was soon realized that light might be thrown on many obscure problems in the causation of infective disease by a precise knowledge of the arthropoda that come into contact with man. This illuminating doctrine was first opened out in 1879,

when Sir Patrick Manson, at that time a plain medical practi- tioner in China, published the essential parts of an experimental proof that the parasitic worm which causes the disfiguring febrile and subfebrile diseases known collectively as filariasis is com- municated from man to man by a common house-haunting mosquito. It is true that long before 1879 seasonal fevers in several parts of the world had been ascribed, not only in popular tradition but also by plausible argument, to the bites of insects, but these vague glimmerings of the truth had not been regarded very seriously, and Manson was the first to demonstrate, by verifiable experiment, that in such cases the insect plays an indispensable triple part, namely, (i) after infecting itself with parasites responsible for the fever by imbibing the blood of a human being infected with them, (2) to provide in its own organs and tissues the appropriate medium for the growth and develop- ment of the parasites so absorbed and finally (3) to carry the parasites so fostered to fresh human victims. The precise manner in which the filariated mosquito passes on its acquired infection was not settled by Manson, but his wonderful discovery originated that new branch of study where a full and exact knowledge of ah 1 the arthropoda that touch man in his person, his dwellings, and his food and drink, finds, as Medical Entomology, a rational application in the control of disease.

Subject-matter. In dealing with the subject-matter of Medical Entomology it is convenient rather than severely logical to group the arthropoda inimical to health in five categories, accord- ing to the nature, the direct effects and the after consequences of their results, namely as (i) simply parasitic, (2) simply pre- daceous, (3) specifically infective, (4) contaminative and (5) venomous, the third and fourth being far the most important.

Simple Parasites. Here are included all those arthropod parasites that are hurtful solely by their presence on or in the body and not by any subsequently disclosed effects. Such are the itch-mites (Sar- coptes) specific to man, and the numerous food-mites, animal-mites, bird-mites, insect-mites, harvest-mites, etc., which in certain cir- cumstances or at particular seasons may attack man, though not normally parasitic on him or in every case parasitic at all in normal habit. Though they usually attack the epidermis these mites may get into the bowel, or the lung, or the bladder. Such also are those muscoid flies which in their maggot stage are constantly and entirely dependent on warm-blooded animals for their existence : two such species of maggots are notorious subcutaneous parasites of man, namely the " macaw worm " (Dermatobia hominis) in tropical America, and the " tumbu " (Cordylobia anthropophaga) in tropical Africa. Bluebottles, flesh-flies and other domestic flies, which normally deposit their eggs or larval progeny in decomposing meat and carrion, may be attracted for this purpose to foul and neglected wounds, or to the eyes, nostrils and other natural orifices of un- clean or incapable humanity, with dire results: the " screw-worm " flies (Cochliomyia in America and Chrysomyia in India) are said to be particularly prone to this deplorably mistaken instinct. Living maggots of many species of flies may find a congenial abode in the human bowel, as also may larvae of other orders of insects. Other simple parasites of man are the " Chigger " flea (Dermatophilus penetrans) common in certain parts of tropical America and Africa, the pregnant female of which embeds herself in the skin; and the " Congo floor-maggot " (Auchmeromyia) of tropical Africa, a maggot which infests native huts like a bedbug and sucks the blood of sleeping people, though the parent fly is harmless. An abnormal and misdirected parasite that, in places where Jarge snakes are numerous, may get encysted in the human viscera, is the larva of the extraordinary wormlike arthropod Porocephalus, the adult of which is a bloodthirsty inhabitant of the lungs of snakes.

Predaceous Arthropoda. To this category may be relegated a miscellany of blood-sucking insects, etc., the bite of which may be painful or may even cause severe inflammation, but is not known to be followed by any specific infection apart from a chance of ordinary septic contamination as a result of scratching. Though t)iere are times and places when these insects may be an intolerable burden to travellers or to country folk, they have no preference for human blood and no particular affection for houses. They cannot therefore be regarded as a standing menace to the public health, although they may be treated with a reasonable amount of suspicion, because some of them are known to spread specific infections among domestic stock, and also because they may be chance mechanical carriers of some individual contamination, or may have parasites proper to themselves which might possibly under certain circumstances be transferred to man. This suspicious assemblage includes many species of mosquitos and gadflies, a lot of midges (Simulium, Psychoda, Culicoides, etc.), and numerous species of muscoid flies (Stomoxys, Haematobia, Lyperosia, etc.) that usually feed on cattle; also various flies (Leplidae, Asilidae, etc.) that normally feed on