Blood vessels in the tail of a young eel
A, C, E: "Venes". B,C,D: "Arteries"
unknown draughtsman of Antoni van Leeuwenhoek
The collected letters of Antoni van Leeuwenhoek. Part XII, 1989, <a href="//commons.wikimedia.org/wiki/Special:BookSources/9026508956" title="Special:BookSources/9026508956">ISBN 9026508956</a>