Wrote Letter 30 of 1680-04-05 (AB 57) to Robert Hooke about the testicles and sperm of a rat and organisms in the gills of oysters and in the sap of vines

April 5, 1680
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Text of the letter in the original Dutch and in English translation from Alle de Brieven. The Collected Letters at the DBNL - De Digitale Bibliotheek voor de Nederlandse Letteren.

The original manuscript on three quarto pages, written and signed by Leeuwenhoek, is preserved at the Royal Society (MS. 1881. L 1. 52).


The figures of a rat's testicle in a jar of water and a little animal that came from it were the only two figures illustrating this letter. The originals were in ink and are preserved in the Royal Society's archives. In the text, these figures appeared together on a separate unnumbered plate in both the Dutch and the Latin editions. The scans on the left sidebar are from the 1686 first edition of Levende Dierkens.

Leeuwenhoek wrote in the letter that he drew Figure 1 "as far as it was feasible to me" (so veel het mij doenlijk was). He had someone else draw the far more complex Fig. 2 for him: "I caused it to be drawn" (ick heb laten afteijckenen).