Samuel Taylor Darling (1872-1925), one of the world's leading experts in tropical diseases in the early twentieth century, investigated malaria, hookworm, amebiasis and other tropical diseases in Panama, the Far East, South Africa, Brazil and the southern United States. As a pathologist, he performed more than four-thousand autopsies among employees of the Panama Canal Company who died between 1905 and 1914. This experience gave him a singular perspective on the anatomical pathology of tropical diseases. The results of his innovative work helped him to develop new concepts about diagnosis and treatment of malaria (spleen index and species-specific mosquito control); amebic dysentery (modified life cycle using rectal inoculation of parasites in kittens); and intestinal parasitosis (improved detection and treatment); tuberculosis (epidemiology among Panama Canal workers); and other diseases common in tropical regions. Darling is also credited with discovering histoplasmosis. For his pioneering work he was named an honorary member of the Royal Society of Tropical Medicine and Hygiene. Andrew Balfour, first Director of the Wellcome Laboratories in Khartoum, considered him "America's foremost tropical al parasitologist and pathologist." This book is the first full-length biography of this remarkable scientist. Primary research was conducted at the Rockefeller Archives, National Archives, Library of Congress in the United States, and libraries in Panama and the former Canal Zone. This work is essential reading for medical historians, and those interested in the history of sanitation and public health, malaria, and yellow fever; and provides a better understanding of the Panama Canal experience, and Rockefeller philanthropy in tropical medicine and hygiene.