None of these series has been created by the simple expedient of taking an existing edition and sending it to the printer—a plan too commonly followed, as is well known to every one who has ever investigated the text of a well-known author, and has found that each edition contains almost all the errors of its predecessors and adds fresh errors of its own. The Oxford texts are the result of the laborious co-operation of editor, publisher, and printer, involving the choice of the most authoritative original—very often the collation of a number of printed originals and sometimes of manuscripts as well—expert attention to the problems both editorial and typographical of which the successful solution produces a well-designed book, and finally scrupulous diligence in the elimination of error. The substantial accuracy of Oxford texts is widely recognized, and is known to be due to the united vigilance of the editors, the publishers (themselves scholars and sometimes editors), and the printers. It is less well known how complex and difficult are the problems which the modern editor has to solve. The scientific editing of English texts is indeed a relatively recent growth, and depends upon the application of principles which in the field of Greek and Latin textual criticism have been elaborated in the course of centuries. It is thus no accident that the work done in English editing in the last five-and-twenty years has been largely in the hands of scholars trained in the Oxford school of _Literae Humaniores_, and has synchronized with the production of the _Scriptorum Classicorum Bibliotheca Oxoniensis_. This series, now popularly known as the _Oxford Classical Texts_, is the only large series of critical texts of Greek and Latin authors produced in recent times outside Germany and able to hold its own in competition with its great German rivals. The texts, which now fill nearly eighty volumes and include the most important writers of the ‘classical’ periods of Greek and Roman literature, have been based upon much fresh examination of the manuscript originals. Some of the editors, indeed, have devoted years to this kind of investigation; the labours of Mr. Allen on the manuscripts of Homer and of Professor Clark and Sir William Peterson on those of Cicero have secured for their authors a permanent place in the long history of classical scholarship.