The _Zone of the Armies_ is, in turn, divided into two sections (1) the "Zone de l'avant," in which military operation of the railways is necessary on account of their nearness to the fighting-line; and (2) the "Zone de l'Arrière," in which the railways can still be operated by the ordinary railway staffs, under the direction of Line and Station Commissions, as in the adjoining Zone of the Interior. Orders given by the Commander-in-Chief in respect to transport in the Zone of the Armies are carried out under the supreme control of an officer now known as the _Directeur de l'Arrière_. The history of this important functionary affords an excellent example of the way in which the whole scheme of operations has been evolved. The "Règlement général" of July 1, 1874,--one of the earliest attempts to meet the difficulties which had arisen in 1870-71 in respect to military rail-transport--was found to be defective inasmuch as it did not apply, also, to those road and rear services ("Services de l'Arrière") which are necessarily associated with the rail services and themselves constitute so important a phase of military transport as a whole. In 1878 an attempt was made to meet this defect by the inauguration of a system of "Services des Étapes"; but here, again, the existence of separate organisations for rail service and road service, without any connecting and controlling link, was found to be unsatisfactory. In 1883 a Commission, presided over by General Fay, was appointed to consider what would be the best course to adopt, and, in the result, there was issued, on July 7, 1884, a Decree creating a "Directeur Général des Chemins de Fer et des Étapes," whose duties were more clearly defined under a Decree of February 21, 1900. In 1908 the title of this officer was changed to that of "Directeur de l'Arrière," and, after further revisions, the scope of his authority and responsibility was eventually fixed by the Regulation of December 8, 1913.