The Native Races was very much in the nature of a compilation, and our knowledge concerning the authorship of its various parts is necessarily less exact than is true of any of the other Bancroft works. Such facts as are at hand come from two schedules--one of his own works, the other of that of the corps generally--prepared by William Nemos, a gifted Swedish writer who entered the library in 1873, subsequently becoming Oak's chief assistant, and ultimately his successor in the librarian's office; from separate information gained by Frances Fuller Victor as to the part of the work done by Oak. (This consists of three different statements, one in a letter to a friend, another in an autobiographical sketch, and a third in a statement copied by Mrs. Victor. Mr. Oak himself refuses to give testimony, doubtless on account of his former intimate personal connection with Mr. Bancroft and his acquiescence in the plan followed, as well as his poor health, which renders him unwilling to enter into a discussion of the question, and from statements in an autobiography of Thomas Savage, chief Spanish interpreter in the library after August, 1873.) The facts as deduced from these sources show that Oak wrote more of the Native Races than any one else, two fifths of the entire work, or to be exact, fifteen hundred and ninety-seven pages out of four thousand. While engaged in this writing, it must be remembered that he also acted as "chief assistant to Mr. Bancroft, manager of all details of this work, as well as that on the History, overseer of the corps of workers, and chief proof reader," duties which so engrossed his time that he wrote principally between eight o'clock in the evening and midnight. The fourth volume on Antiquities is his work entire, as is also the fifth on Primitive History, except the introductory chapter on the Origin of the Americans, in the preparation of which it would appear that Bancroft had a hand (Lit. Ind., 570), and the last three chapters dealing with the tribes of Central America, the authorship of which the writer has no means of determining. Nemos says, however, that he prepared "a good deal of clean manuscript" for this volume as well as for some others. To Harcourt the division of the field as already given points as the author of the second volume. Oak wrote the introductory chapter entitled General View of the Civilized Nations, and also the chapter on the Aztec Picture Writing and Maya Arts Calendar and Hieroglyphics. Bancroft is the author of the chapter on Savagism and Civilization, and Nemos is to be credited with the writing of some parts. As Harcourt wrote six hundred and thirty-six pages of the Native Races, and there appears but one reference to his writing in connection with another volume, and that a chapter of a hundred and fifty pages, we may conclude that the remainder of Volume II is from his pen.