Wilhelm Doenitz was a German anatomist, surgeon and medical researcher who worked for many years in Japan.
Doenitz was born in Berlin, where as a child he showed an interest in natural history and drawing. Following medical studies from 1859-1864, he was appointed an assistant the Anatomical Institute, Berlin and earned the title of Professor in 1873. In the same year he married Martha Schirmeister and was appointed Chair of Anatomy in the new Academy of Medicine in Tokyo, Japan.

In Japan, Doenitz introduced the practice of anatomical dissection, plenty of material being available as a product of executions by the courts. He was also involved with improving sanitation and hospital administration. In 1877, during the civil war, he served as a surgeon in Nagasaki. Despite his workload, Doenitz always found time to pursue his interest in natural history in Japan, making extensive collections of insects and plants. Notably, he collected at Mount Nantaisan, Nikko, and Mount Fuji, in 1875, and at Mount Kanosan and Yumoto, near Nikko, in 1876.

Following a break in Europe in 1880 he settled in Saga, Kyushu, for six years. He then returned to Berlin, working with Robert Koch at the Hygienic Institute and Institute for Infectious Diseases (Institut für Infectionskrankheiten). In 1893 he was appointed director of the Bacteriological Laboratory in Bonn, specialising in research on cholera, and in 1896 returned to Berlin. His later years were spent as director of the Scientific Department at the Institute for Infectious Diseases, where he remained until his death.

As well as his work on anatomy and bacteriology, Doenitz was recognised for his contributions to parasitology and taxonomy of mosquitoes and ticks. The sedge species Carex doenitzii Boeckeler commemorates him.

Sources:
G.H.F. Nuttall, 1913, "In Memoriam. Wilhelm Dönitz", Parasitology, 5: 253-261
J. Ohwi, 1965, Flora of Japan, 1: 8.