Description: [edan-image:id=siris_sic_5844,size=250,left]A staff-favorite story in the Smithsonian’s history is that of the Megatherium Club — a revolving group of young naturalists who made the Castle their temporary home in between expeditions to the outer reaches of the United States. Who could not be intrigued by this photo of the Club where they look to be sharing a joke, or a plan?