Hailed as the "Prince of World Physiology," Ivan Pavlov continues to influence scientists today. His pioneering research on digestion, the brain, and behavior still provides important insights into the minds of animals--including humans--and is an inspiring example of imaginative experimental technique. Pavlov graduated from the theological seminary in his native Ryazan, Russia, in 1869 but almost immediately switched to medicine and enrolled at St. Petersburg University. He became interested in the physiology of circulation and digestion, which led him to the study of conditional and unconditional reflexes. He conducted thousands of experiments with dogs, developing a way to use a dogs salivary glands as a window through which to observe the workings of its brain. Pavlov lived through the Russian Revolution and the civil war that followed it. Lenin himself recognized his genius and provided financial backing for his research; the new Soviet government built a research complex dedicated exclusively to his experiments. Pavlov was honored for his contributions to science with the Nobel Prize for Physiology in 1904. Oxford Portraits in Science is an ongoing series of scientific biographies for young adults. Written by top scholars and writers, each biography examines the personality of its subject as well as the thought process leading to his or her discoveries. These illustrated biographies combine accessible technical information with compelling personal stories to portray the scientists whose work has shaped our understanding of the natural world.