The English edition of the biological portions of Swammerdam’s monograph on the may-fly. The original Dutch edition (1675) was a bulky volume of 460 pages with an extremely wordy title. Swammerdam said he wrote this treatise “to give us wretched mortals a lively image of the shortness of the present life, and therby to induce us to aspire to a better.” Never was a sermon more laboriously annotated with a scriptual basis for almost every word. The English editor has omitted all religious references and left is a treatise of 44 pages which shows us Swammerdam at his best. He was the first to throw any light on the anatomy of metamorphosis of insects and is one of the founders of experimental biology. “Even in his perversely verbose treatise on the may-fly, we find that directly he abandons his crazy theology and applies himself to the objective aspects of the research he steps into his proper place among the big men of his country.” Swammerdam had started his work on the may-fly as early as 1667, and mentions dissecting the nymphs in 1670, and making notes on the metamorphosis in 1671. His Ephemeri Vita contains some very remarkable pieces of minute anatomy. The figures, drawn by himself, are the best early representations of the dissection of an insect. The English editor/publisher was Edward Tyson, famous for his work on “the missing link”, entitled ‘Orang-Outang, sive homo Sylvestris: or the Anatomy of a Pygmie compared with that of a Monkey, an Ape and a man’ (1699). Collation: Pp (8), 44, (8). With 8 engraved plates numbered I-VIII, of which two are large and folding. Binding: Disbound, marbled spine strip. Earlier in a sammelband together with papers by Kober, Paulli, Bartholin, a.o. References: Cole, 270-305; Singer, Short History of Biology, 160-162; Montagu, Edvard Tyson, 121-125; Norman Library 2036; Hagelin, Rare and Important Medical Books, KIB, 96-97.Christie’s Norman Sale 813. Waller 11967 (the original Dutch edition Amsterdam 1675).