Victor Scheffer (The Year of the Whale, etc.) started being a zoologist in 1925, when he studied entomology ""under an exceptional teacher""--and when, in the world at large, wildlife management meant maximizing its commercial potential. In 1972, after a lifetime in government service, he was chosen to implement the first Marine Mammal Protection Act. This modest, appealing book is at once a record of his life's work, an informal history of sea-mammal study, and a mirror of changing perceptions. But it is also about being a biologist-at-large--part researcher, consultant, administrator, teacher, part public official and part special advocate. By good fortune and propinquity, Scheffer served his ""internship"" as a ranger-naturalist at Mount Rainier (where he saw life zones--a new concept--""stacked like layers on a cake"") and on a research voyage to Alaska--""an example of first stage, or exploratory zoology,"" aimed at learning what species are where. Soon he was in the Aleutians--in time to see the last of the shore-whaling stations, the last of the ptarmigans (before mainland house rats destroyed them), the last of the Aleut culture. But the larger part of his work in the region involved the study of fur-bearing seals (""How could we estimate the age of an individual seal? How determine the death rate within each age class? How learn the age at which the average male or female begins to breed. . .?"") in order that ""as many seal skins as possible"" could be harvested each year. Day to day, he waded in grease and dung; in the background loomed the collapse of the North Pacific treaty to protect the seals from overexploitation. In time, he raises the attendant ethical questions (about thinning herds, eliminating ""weed species""); he teaches--and a student asks what he means by ""higher mammals""; he hikes with Justice Douglas (1958) along the Olympic seacoast to preserve a wilderness strip--and organizes a local Nature Conservancy chapter. He's called to the Antarctic and Guyana, attends international confabs, and gets hell from a congressman for dragging his feet. The easy, unpressurized mix is not a classic testament; but, like a living-room slide show, it's honest, approachable, and maybe best of all, a model career within general reach.