Experimental models of infective endocarditis antedate Garrison and Freedman's work in 1970. The hypothesis of the role of parasites (microorganisms) microscopically observed in vegetations and cardiac valves of patients with endocarditis was first put forth by Winge in Sweden in 1869. Winge's work led Klebs and Rosenbach in Germany to establish, between 1878 and 1881, an animal model of experimental endocarditis in which the aortic valves of rabbits were perforated with a metallic probe (loaded with septic material) introduced through the carotid artery. Ten years after Winge's work, Pasteur emphasized the importance of bacteriologic "blood cultures." During the period 1881-1886, Netter and Grancher (Pasteur's associates) introduced a method for drawing aseptic blood samples from patients with clinical endocarditis and performing bacteriologic blood cultures. In Vienna in 1885-1886, Orth, Weichselbaum, and Wyssokowitsch further developed Rosenbach's procedure of inducing experimental endocarditis by injecting material from a bacterial culture into a rabbit's ear vein. The development of an experimental model of endocarditis by investigators in the latter part of the nineteenth century provided anatomopathological and bacteriologic data that in turn led to a better understanding of infective endocarditis.