Letter, from Antoni van Leeuwenhoek to the Royal Society, dated at Delft Signed letter Examination of gall-nuts found on oak trees; further discussion of the germination of plants and the impossibility of transferring an embryo from one seed to another Original figures no longer exist Transcribed and translated in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, vol 6, p 47 14 May 1686