John Merle Coulter contributed tremendously to the rapid advance of botany in North America during the late nineteenth and early twentieth centuries. An exploring mind, deeply religious spirit, and scientist's respect for truth, combined with singular personal charm, made of him not only a missionary in science, but a natural leader among the botanists of the United States. He set for his goal the building of a complete structure of the house of botany, and he took the lead in organizing defined branches of study which eliminated the waste of duplicated effort. The thread of this story of...