Letter, from Antoni van Leeuwenhoek to the Royal Society, dated at Delft Signed autograph Observations of rotifers, which originate from the roots of duckweed, and their parasitic worms Read to the Royal Society on 6 December 1704 5 red-chalk figures attached English translation is EL/L3/70 Transcribed and translated in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, vol 15, p 63 English translation printed in 'Philosophical Transactions', vol 24, no 295, p 1784 4 November 1704