Found, Then Lost, Then Found Again,

it appears that the founts of knowledge, museums,

do sometimes lose wonders of nature, in the decade before he published On the Origin of Species, Charles Darwin corresponded with Japetus Steenstrup, then head of the Royal Natural History Museum in Denmark (the precursor to the current Natural History Museum’s Zoological Museum), who lent the scientist some fossilised barnacles in November 1849 for his Species research. “It is a noble collection, & I feel most grateful to you for having entrusted them to me,” Darwin wrote Steenstrup when he received the box of barnacles in January 1850. “I will take great care of your specimens.” (According to the History Blog, when the packages were late, Darwin was so concerned that he actually put an ad in the paper offering a reward for their return.),

when she was studying the correspondence between the two scientists, Hanne Strager, the head of exhibitions at The Natural History Museum of Denmark, noticed in the correspondence that Darwin mentioned a list of 77 additional barnacles he had sent as a gift when returned the borrowed barnacles to Steenstrup in 1854. That list was found in Steenstrup’s papers, and the museum was able to locate 55 of the barnacles, with the original labels—not an easy task, because they had not been kept together; as The History Blog notes, there wasn’t a reason to keep them together: “On the Origin of Species was five years away. The barnacles were seen as specimens like any other, not the curated collection of a great pioneering scientist. They were spread throughout the museum collection according to their species.” The museum has since put the specimens on display. Most of the missing barnacles come from one genus, and were probably lent out to another institution or scientist who never returned them, 

a number of Darwin specimens have been lost and then rediscovered, including a beetle he discovered on an expedition to Argentina (which was named Darwinilus sedarisi in the scientist’s honour 180 years later),

 the taxidermied remains of a tortoise he captured in the Galapagos and kept as a pet, 

 and a Tinamou bird egg he collected during the HMS Beagle expedition, and there was me thinking that exhibits in a museum were safe!