An eminent paleontologist with the soul and skill of a poet, Loren Eiseley (1907-1977) was among the twentieth century's greatest inheritors of the literary tradition of Henry David Thoreau, Charles Darwin, and John Muir, and a precursor to such later writers as Stephen Jay Gould, Richard Dawkins, and Carl Sagan. After decades of fieldwork and discovery as a "bone-hunter" and professor, Eiseley turned late in life to the personal essay, and beginning...