John Steinbeck's novel, Sweet Thursday, went through several printings, of which two jacket covers are shown above. The original hardback jacket cover shows Cannery Row and "Doc" Ricketts lab. A later jacket cover for paperback printing shows "Doc" and the "Seer" in a fascinating juxtaposition. The novel "Sweet Thursday" is noteworthy to marine biologists and naturalists for many reasons. Perhaps the most important reason is its portrayal of a marine biologist (naturalist), albeit somewhat fictional. However, the book is also significant for its style of natural history passages and from describing the Monarch Butterfly Migration festival to describing tidepools, rattlesnakes, and the natural landscape of Monterey and coastal California. And of course, there is also a portion of the novel that is about evolution and biologists that makes the novel of interest to marine biologists. Who was Jinglebollix? Dr. Joel Hedgpeth believes he knows who it is? More on that later. Perhaps the next printing of Sweet Thursday might have a jacket cover painting of Doc, Jinglebollix, Seer, and a monarch butterfly.