The first full-scale biography of William Harvey for younger children emphasizes his medical findings and subordinates his personal life, but it lacks the clearly-labeled anatomical drawings that would make those findings meaningful. His discovery of how the heart controls the circulation of the blood and his investigation of the processes by which animals produce their young are simply and logically explained. He impressed his precepts upon his students--ask questions, make dissections to find the answers, rely upon your own observations--and the moral of his methods is impressed upon the reader. References to his predecessors and his immediate successor establish his contribution to medical science. With few lapses, conversations and personal anecdotes are attributed to contemporary sources. But the illustrations, in the style of old engravings, contribute more to story than to science and make this supplementary rather than self-contained source.