Moore often used natural objects as sources for his sculptures. He kept boxes of bones, flints, and shells close at hand in his studio. The shape of this sculpture, and the way it interlocks, seem to be derived from bones and joints. Even at their most abstract, his work has an organic quality. Moore commented: ‘The observation of nature is part of an artist's life, it enlarges his form [and] knowledge, keeps him fresh ... and feeds inspiration.’