Director of Army Postal Services. The Service of Army Signals is controlled by the General Staff, and the Medical Services by the Adjutant-General’s Branch, for the reasons previously explained, in describing the organization of the Staff, in Chapter VI. All the other Directors, and their representatives with Subordinate Commands, work under the supervision of the Quarter-Master-General’s Branch of the Staff. Besides the above Directors, and the Administrative Services they control, the following Officials and Departments form part of the General Head-Quarters of the Army in the Field. A _Deputy Judge-Advocate-General_, for legal advice, and a _Principal Chaplain_ are attached to Head-Quarters of the C.-in-C., and are placed under the Adjutant-General. An _Accounts Department_, under the Financial Adviser attached to Head-Quarters, and a _Record Office_, to deal with correspondence, will be established at the Base. Of the officers enumerated above, the first four Directors, those of Army Signals, Medical Services, Transport, and Supplies, accompany General Head-Quarters in the field. The remainder are usually attached to the Head-Quarters of the Lines of Communication, where the Services they administer are mainly employed. ORGANIZATION OF THE LINES OF COMMUNICATION It is desirable, therefore, that a sketch of the organization of the Administrative Services should be prefaced by one of that of the Lines of Communication (L. of C.), on which they mainly act. The normal L. of C. for which these Services are calculated is a Railway 100 miles long reaching from a Sea Base to Railhead, and thence by two roads 30 miles long to two Advanced Bases. The _defence_ of the L. of C. is now entirely separated from its _administration_, and is entrusted to an Officer styled the _Commander of L. of C. Defences_, who is also responsible for its military government when in hostile territory. To this officer are allotted certain “L. of C. Defence Troops” (two battalions for the normal L. of C. laid down). The L. of C. is divided into sections for defence, each under a subordinate “L. of C. Defence Commander.”