Wrote Letter L-485 of 1712-03-01 to the members of the Royal Society about the skin and flesh of a whale, its seminal vessels, and its blood with comparisons to the blood of other fish

Leeuwenhoek's self-publications are the source for the summaries of his 165 letters self-published and thus self-numbered letters. This letter was not among them.

Of the letters from L-405 1702-04-28 to L-487 1712-06-10, those letters with scientific observations, including this one, were all addressed to members of the Royal Society and almost all of them were excerpted in Philosophical Transactions.