In looking at the map of the Great Lake region, you have all noticed the backward bending thumb of Michigan projecting into the icy waters of Lake Superior; yet but few of you, perhaps, have realized that extending along that thumb there runs a band or ring of native copper. It does not, like most gold or silver bands, extend around the finger, but along it—from the base of the hand to the end of the thumb—this central band lies embedded in the flesh binding all together. Shall we now dissect it, laying bare its flesh, muscle, and bone, and try to explain its marvellous organization ?