Johannes (Jaroslaw) Marcinowski, a German neurologist, was born in Breslau, Poland, on November 13, 1868, and died in Tübingen-Waldhausen, Germany, on February 13, 1935.

He was the son of Johanna and Johann Gottlieb Marcinowski; his father was an administrative councilor. He attended a cadet training college and graduated as an officer. He was wounded in the course of his military career and subsequently devoted himself to medical studies, graduating from the University of Breslau as a doctor of medicine in 1894. From 1901 onward he worked as a neurologist in different treatment centers and in 1907 he founded his own center (Haus Sielbeck bei Eutin, in the province of Holstein).

Carl Gustav Jung drew Freud's attention to one of his papers. Freud responded: "Today I received a charming letter from Marcinowski, in which he declares himself to be our staunch supporter and comrade in struggle. He tells me that three further...