The Ichneumon and Geoffroy Saint-Hilaire
Étienne Geoffroy Saint-Hilaire was the chair of zoology at the Museum of Natural History in Paris, but he was only 26 years old when the expedition arrived in Egypt. As one of the members of the Physics (natural history) section of the Institute, he took responsibility for studying the animals and the fish of Egypt. One of the local animals that attracted his attention was the ichneumon, or Egyptian mongoose.
Geoffroy would have known that the ichneumon was described by ancient authors such as Diodorus, who wrote about the mongoose controlling the population of crocodiles in Egypt by eating crocodile eggs wherever it finds them. Geoffroy would also have known about the narrative of Pierre Belon, who traveled from France to Egypt two-hundred fifty years before Napoleon’s expedition and published a narrative of his travels in 1553. The mongoose was among the many animals Belon observed, and the woodcut illustration in his book was influential on several generations of naturalists. Many of them had trouble figuring out the curious tail in Belon’s illustration, however. The woodcut artist lacked space to show the entire animal, so the end of the tail was depicted over the animal’s back, instead of extending out straight or drooping in a more natural position.
Geoffroy did not have that problem. The huge paper used to print the Description de l'Égypte afforded plenty of space to show the entire animal, although not enough room for a life- sized depiction. The image of the ichneumon shares space on the page with the Egyptian rabbit. It was one of 42 plates contributed by Geoffroy to the Natural History section of the Description. He prided himself on collecting specimens with care and making observations with exacting detail, especially when doing anatomical dissections.
Although Geoffroy collected and observed a multitude of Egyptian vertebrate animals, he did not prepare the illustrations. These were done by artists, such as Henri-Joseph Redouté, younger brother of the famous botanical illustrator Pierre-Joseph Redouté.
There was plenty to draw. After returning to France, Geoffroy and J.C. Savigny needed about four dozen cases to pack all of their zoological specimens for transport to Paris. The specimens that seemed to most interest Geoffroy were those of the Nile fish, such as a previously unknown species of lungfish with multiple dorsal fins that he called Polypterus bichir, or the dramatic forms of two pufferfish that were also included in the zoological section on Fishes of the Nile.
It was while working to complete the section on ichthyology in the Description de l'Égypte that Geoffroy made a discovery about the comparative anatomy of fish. He demonstrated that they were not fundamentally different from other vertebrates in their internal organization, as naturalists then thought. He went on to argue further that all vertebrates have a basic unity of form.