After a distinguished career as a collaborator of Prof. Hugo de Vries, the famous geneticist, Karel Bernard Boedijn (born June 29, 1893, at Amsterdam) became a mycologist, and it is in this latter capacity that he will be primarily remembered. He had already started to pay attention to the fungi during his Amsterdam period when C. van Overeem, Miss D. M. G. de Haas (who later married van Overeem), and Boedijn banded together and called themselves the “Mycologisch Museum te Weesp”. They started building up a collection which, however, never became very big. After some years van Overeem accepted a position in the Herbarium of the Botanic Gardens at Buitenzorg (now Bogor) in Java, where he died after a short but active period (1921-1927). The collections on liquid of the “Mycologisch Museum” are now at the ”Hugo de Vries-Laboratorium”, Amsterdam, while the dried material, taken to Java by van Overeem, will be found in the collections of Herbarium Bogoriense.