1 Underside of stinging nettle leaf 2 Beard of wild oat used in Hookes hygrometer. 3 Section of head of wild oat. 4 Hookes hygrometer. From Robert Hooke Micrographia London 1665. Engraving . Editorial Stock Photo - Afloimages
1: Underside of stinging nettle leaf 2: Beard of wild oat used in Hooke's hygrometer. 3: Section of head of wild oat. 4: Hooke's hygrometer. From Robert Hooke 'Micrographia' London 1665. Engraving .