"Hornbook" originally referred to a sort of instructional aid for children to learn how to read; "A child's primer consisting of a sheet of parchment or paper protected by a sheet of transparent horn," as defined in Webster's Dictionary. History: Hornbooks differed widely but typically consisted of a sheet of paper, with text that progressed in the following manner:
The alphabet in upper and lower case, a shortened syllabarium, the benediction and the Lord's Prayer. It was covered with a thin transparent sheet of cow's horn tacked to a paddle-shaped piece of wood. A leather cord was often looped through a hole in the paddle so that students could hang the hornbook around their necks or waists. In modern legal circles, a hornbook is generally a one-volume treatise on an area of the law, written for students. "[Th]e student who remains puzzled after reading the casebook and attending class, and who does not want to become a fixture outside the professor's office door, seeks refuge in the hornbook."
As for Glannon's book: "[T]here has emerged a group of books that might be termed hybrids between hornbooks, outlines, and study aids. These books combine a basic hornbook description of the subject matter that is shorter and simpler than the hornbook but deeper and less black letter than most study aids. The books also include problems or questions to use as study aids. The relatively recent Fundamentals of Pretrial Litigation and Civil Procedure: Examples and Explanations, provide the best examples of this subgenre". Jeffrey W. Stempel, Book Review: All Stressed Up But Not Sure Where To Go: Pondering The Teaching Of Adversarialism In Law School: Readings On Adversarial Justice: The American Approach To Adjudication, Stephan Landsman, 55 Brooklyn L. Rev. 165, 174 (1989) (footnotes omitted). — Bob Stock, UCLA School of Law '98.