The Fungus That Makes Mummies

In 1647, construction workers carrying out repairs on the Church of Saint Andrew in the small city of Venzone, in the province of Udine, Italy, accidentally broke open a tomb in the churchyard. Inside was found the perfectly dried body of a man who appeared to be of average height and possibly rotund during his living days. His body had now shrunk to only 33 pounds, or about 15 kg. But curiously, it hadn’t decomposed.

Over the next four centuries up to present times, a total of 42 bodies have been dug up from the tombs in the churchyard. All the bodies had undergone spontaneous mummification a short time after they were buried. Their skins have turned yellow-brown and look like tanned leather. The muscles, including the heart, have been reduced to thin membranes, while internal organs such as kidneys and pancreas have disappeared. The brain is one-third of its volume. These mummies weigh anywhere between 22 and 44 pounds, and although greatly altered, the forms and features of the bodies are well preserved and entirely recognizable.

Investigation revealed that the curious transformation had occurred inside eleven tombs, all of which are situated near the high altar. But none of these eleven tombs show any signs of special construction—they are of masonry, covered and closed by slabs of stone.

In an article published in 1906, writer F. Savorgnan de Brazza discusses several hypothesis regarding the cause of the mummification. The presence of salts of niter, alumina or lime may have produced such desiccation, but no such salts have been found in the tombs.

Brazza believes the mummification was caused by a fungus, Hypha tombicina, whose spores were known to be prevalent in both the tombs and their wooden coffins.

“The Hypha tombicina,” Brazza wrote, “is very eager for moisture. It absorbs it by means of the microscopic suckers that serve it as roots. It develops and multiplies with great rapidity and dries the body before they can enter into decomposition.”

Attempts to cultivate this species of Hypha, however, Brazza laments, have been without success.

At the time of de Brazza’s writing, the number of mummies in Venzone was numbered at 42. An earthquake in the area in 1976 has since reduced the number to only 15. Their declining number has made it rather difficult to study precisely what the conditions behind their mummification had truly been. Furthermore, the dead are no longer buried in churches, so their number is unlikely to increase in future either.

For now, the fungus-theory is little more than speculation. In 1983, University of Minnesota professor Arthur C. Aufderheide visited the site and was allowed to culture two samples for fungi as well as collect soil, wood and brick samples for analysis. None of the microorganisms identified fitted the original description of Hypha bombicina (the spelling as used by Aufderheide in his descriptions.) Besides, Aufderheide noted, that the description of Hypha bombicina was too insufficient to differentiate it from many other organisms in modern taxonomy. Aufderheide concluded that the most likely explanation of the preservation in Venzone was the well-drained limestone soil and the water protection of the tombs by the overlying church.

Venzone mummies continue to intrigue scientists and tourists who visit this site in great numbers. Some of the mummies are now visible in the Crypt of the Cemetery Chapel of Saint Michael located in S. Andrea Apostolo Cathedral churchyard.

Photo credit: Joadl/Wikimedia

Photo credit: Jean-Marc Pascolo/Wikimedia