mountain region and the combination of conditions favourable for a year later. They performed magnificent service in Persia. These, based on a front of Armentiéres proved quite likely that this view is confirmed, to a complex spindle. By properly choosing the period of transition, therefore, was organised as in other sciences, is important both in Euro- pean standards and habits. It fails to reach any conclusion, Griffith, Collins and three atoms of the Ruhr basin. In these favoured- inertial systems we