Recent Advances in Medical Science

241 The preliminary survey of protozoology, including chapters on ecology, mnorphology, physiology, reproduction, and variation and heredity in Protozoa, is still inadequate, but it serves to suggest the wealth of data and the extensive literature now available concerning these simplest but far from simple animals. The author undoubtedly will wish to revise certain statements before reprinting. The taxonomic section of nearly 500 pages is the real contribution. Here is presented a well-illustrated synoptic view of the Protozoa that is of great value for the identification of many free-living and parasitic forms. Fur-thermiore, brief but well-chosen bibliographies point the path toward a more complete view of the nearly 20,000 known species. Prepared as the Rede Lecture delivered before the University of Cam-bridge, this eloquent address gives impressive evidence of the progress of snedical science and of the significance of its recent advances to the civilized world. The author presents an optimistic outlook for future developments with a challenge for the public health administrator, the health educator, and the scientific investigator. He likewise properly directs attention to some of the social and economic factors involved. Marked progress is said to have followed the realization that the experimental method is the royal road to discovery. The human body, from the viewpoint of health and disease, is regarded largely as a problem of coordinated and balanced chemical reactions. The author states that: "Once a biological observation has been made, be it physiological, pathological or clinical (and biological discoveries are always the most difficult to make in medical science), the investigator of the present day knows that the observed phenomenon will be extended and interpreted in terms of chemistry." Consideration is given briefly to advances in the control of human disease (including recent data on pneumonia), to changes in the physique and health of the population (with reference to increased height and weight of children and the influence of changes in food habits), to variations in child mortality and in ill health in relation to social and economic conditions. While the author stresses the higher infant mortality rates and greater incidence of chronic illness among persons of low economic status, he also states that with the increase in the standard of living, diabetes mellitus, angina pectoris, and appendicitis are becoming more frequent "and will probably continue so to do, until medical science has discovered the particular mistake in the mode of living of those with …