6 Stamps of topic "Biology"

All 6 stamps of the topic "Biology" of the Deutschen Bundespost (german post BRD). The sort is in reverse chronological order, so the newest stamps are at the beginning.

Stamp: Gregor Mendel (Biologe), Vererbungslehre
Gregor Mendel (Biologe), Vererbungslehre
Stamp: Otto Warburg (Biochemiker)
Otto Warburg (Biochemiker)
Stamp: Fossil: Fledermaus
Fossil: Fledermaus
Stamp: Fossil Urpferd
Fossil Urpferd
Stamp: Fritjof Nansen (Polarforscher, Zoologe)
Fritjof Nansen (Polarforscher, Zoologe)
Stamp: Alexander von Humbold (Naturforscher)
Alexander von Humbold (Naturforscher)