Among professor Sven Nilsson's (1787–1883) papers is a small envelope with littlephotographs of crania from Gibraltar. Among them are two images of a Neanderthal skull from Forbes Quarry. Nilsson got the envelope from the English naturalist George Busk (1807–86) at the congress for prehistoric archaeology in Norwichand London in 1868. The 1860s was a period of upheaval. The discovery of the Palaeolithic Stone Age and Darwin's evolutionary theory had changed views of the past and humankind's role in nature. The Neanderthal finds complicated matters further. Nilsson had studied the Forbes Quarry skull already at the meeting of the British Association in Bath in 1864. Under applause, he was asked to solve the riddleof the Neanderthals. Nilsson declined the request and thus lost the opportunityto become one of the first Neanderthal experts.