SOUTHERN CALIFORNIA: An Island on the Land By Carey McWilliams (Peregrine Smith: $9.95). Southern California has been perceived as a place apart since it was first explored by Europeans: Several attempts were made to divide California along the line of the Tehachapis, and the U.S. Congress probably would have approved the 1859 vote to partition the state if the Civil War hadn't intervened. Carey McWilliams' classic history traces the development of both the myth and reality of the region. The popular image of Southern California has always contained a large element of fantasy, beginning with the spurious picture of the jolly life in the days of the Old Missions that ignored the wholesale slaughter of the Indians. (In 1783, Governor Fages filed an official complaint about Father Junipero Serra's cruelty to his new Christian converts.) McWilliams devotes entertaining chapters to the cults, booms, busts and frauds that brought people and water to the once desolate Southern California chaparral. Although the text cries out for illustrations, McWilliams' book is ideal reading for anyone interested in how L.A. got to be what it is.