Since several influenza pandemics in preceding centuries were already well-known and had come from the orient, Jordan first considered Asia as the source. But he found no evidence. Influenza did surface in early 1918 in China, but the outbreaks were minor, did not spread, and contemporary Chinese scientists, trained by Rockefeller Institute for Medical Research (now Rockefeller University) investigators, stated they believed these outbreaks were endemic disease unrelated to the pandemic [3] . Jordan also looked at the lethal pulmonary disease cited by some historians as influenza, but this was diagnosed by contemporary scientists as pneumonic plague. By 1918 the plague bacillus could be easily and conclusively identified in the laboratory [3] . So after tracing all known outbreaks of respiratory disease in China, Jordan concluded that none of them "could be reasonably regarded as the true forerunner" of the pandemic [3] .