A considerable mass of memoranda on the early history of libraries has been gathered by the author of this essay during the last twenty-five years, and out of this material various essays have been published from time to time on Antediluvian Libraries, Medieval Libraries, Some Old Egyptian Librarians, etc. The fact that the unworked mass of modern information through excavations is so great as to put off for a long time still a systematic treatise, has led to the plan of publishing these essays and addresses from time to time as completed and in uniform style. Although written for very different audiences and in various methods, each is an attempt to gather information not generally accessible and to be, so far as it goes, either a contribution to knowledge or to the method of knowledge, a sort of preliminary report or investigation in the field, pending full and systematic report. The nucleus of this essay on the Beginnings of Libraries was an address to the Library School of the New York Public Library at the beginning of the academic year 1912-13, and takes its color from this fact, but it has been freely enlarged. The writer owes special thanks to the American Museum of Natural History in New York.