The Genus Spirorchis MacCallum, 1918 (Digenea: Schistosomatoidea) and the Early History of Parasitology in the United States.

We know little about the founders of our discipline apart from their scientific contributions and brief biographical sketches, most frequently in published obituaries. A number of years ago, Ralph Lichtenfels, then Director of the National Parasite Collection, sent me photocopies of letters between Henry Baldwin Ward, Horace W. Stunkard, George A. MacCallum, and William G. MacCallum dating from the early years of the 20th century that hinted at a series of conflicts centered on the proposal of Spirorchis MacCallum, 1918 (Digenea: Schistosomatoidea). The description of a fluke that matured in the blood of a tetrapod and that was morphologically similar to the schistosomes of humans was in its time a transformative discovery; and the scientist who published it would have garnered some scholarly recognition. Herein, I provide an historical account of the issues and the motives of each individual and the eventual resolution of these matters.