John Steinbeck allowing Steinbeck to spend a full day on the set of "The Grapes of Wrath" and the next day on the set of "Of Mice and Men." In the 1930s and 1940s, Ed Ricketts strongly influenced Steinbeck's writing. Steinbeck frequently took small trips with Ricketts along the California coast to give himself time off from his writing and to collect biological specimens, which Ricketts sold for a living. Their joint book about a collecting expedition to the Gulf of California in 1940, which was part travelogue and part natural history, published just as the U.S. entered World War II, never
John Steinbeck who would go on to write a classic early textbook on ecology. Ricketts became a proponent of ecological thinking, in which man was only one part of a great chain of being, caught in a web of life too large for him to control or understand. Meanwhile, Ricketts operated a biological lab on the coast of Monterey, selling biological samples of small animals, fish, rays, starfish, turtles, and other marine forms to schools and colleges. Between 1930 and 1936, Steinbeck and Ricketts became close friends. Steinbeck's wife began working at the lab as secretary-bookkeeper. Steinbeck helped on an informal basis.