He was appointed head of the Natural Sciences department at the Romanian-Soviet Studies Institute in 1947.

Albert Thommen carried on the biologist career, studying at Dresda University.

During 1954-1957, Fuhn was an active researcher at the Biology Institute of the Romanian Academy in Bucharest.

On the pretext of not having finished his studies, he was dismissed in 1958, even if that year he had been appointed main researcher in the Collective Fauna R.P.R.

His collection was transferred to Grigore Antipa National Museum of Natural History and is still a valuable basis for the study of the variability of amphibians and reptiles.

Fuhn was the first Romanian zoologist to grasp that species identification is not enough in herpetology: analysis and classification of subspecies is also of great importance.