1678: the Royal Society in transition after Oldenburg's death
After the death of Oldenburg in September 1677, Philosophical Transactions entered a period of turmoil. For 138 (some sources say 136) numbers over 12 volumes, Oldenburg had been the only editor. He relied for manuscripts on his extensive personal international network, he paid for the printing out of his own pocket, and much of the distribution went back out to that personal network, including van Leeuwenhoek.
In November 1677, Robert Hooke and Nehemiah Grew were elected the Society's two secretaries to replace Oldenburg and Thomas Henshaw, who had made his mark as an alchemist. No one involved with the Society had the contacts to solicit new articles or the funds to continue paying for the printing of Philosophical Transactions. It was in this same month that Hooke successfully demonstrated Leeuwenhoek's "exceedingly small animals".
According to Birch's records of the Society's discussions, based on Hooke's notes, in January 1678, Hooke argued not to continue the journal, and Grew argued otherwise. The Society voted to publish articles from Oldenburg's backlog, so Grew published number 139 in February 1678.
Meanwhile, Leeuwenhoek waited.
Later that year, Grew published in number 140, as two articles, excerpts about teeth, bones, and hair from one of Leeuwenhoek's letters, that of May 31, 1678 (AB 39).
Hooke's Microscopium
Leeuwenhoek's letters were published in Philosophical Transactions without response, with one exception. Nehemiah Grew responded point-by-point to the letter of April 21, 1676, a response longer than the letter itself.
In spring 1678, in Microscopium, Hooke also responded to one of van Leeuwenhoek's letters, again at greater length than the letter itself.
Apparently he did so without Leeuwenhoek's permission, who wrote to Grew on May 31, 1678:
My observations ... which have been placed by Mr Hooke in between the results of his research, have been sent to me by that gentleman. I prefer for the future to have my observations inserted in the Transactions, party because previous ones were published in them, partly because I am not inclined to edit a book, although I am repeatedly advised to do so.