The accumulation of reported cases is going forward so rapidly, that the question of making them available to the busy practitioner is one which grows more serious every year. As long as the careful opinion of one man has any weight with another, cited decisions will be of effect in determining the fate of a litigation. The problem is then how to enable court and counsel, each in different ways closely pressed by work, to know what it is that other lawyers have done, and are doing in the same line of inquiry. Digests, themselves too numerous to be readily examined, and many of them most imperfectly constructed, are not enough. Still less so is the scientific treatise which, holding itself free from the entangling details of case-law, serves only to formulate leading doctrines. The need of the worker, both at the bar and in his library, has called into existence the modern textbook, which tries to combine, sometimes with great success, two almost contradictory purposes. For, if we put aside the exceptional instance of essays upon small subdivisions of the law, in which an exhaustive statement of the cases and a free discussion of theory are both possible, it is exceedingly difficult to give the searcher for precedents and the investigator of these wider considerations, without which mere decision has no solid basis, each the special material he seeks.