Letter, from Antoni van Leeuwenhoek to Robert Hooke, dated at Delft Discussing fibres of muscles of mammals and fish; observations of hair-growth on Leeuwenhoek's hand; discovery of the nucleus in the erythrocytes of fish; discussing the structure and growth of oyster shells Six figures in red chalk Five copies of engravings Transcribed and translated in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, vol 3, p 383 B&W negative, red chalk drawing of muscle fibre and fish erythrocytes, Box N101. IM/005321 March 1682