According to the principles laid down in the "Field Service Manual" it is to the divisional cavalry that the task invariably falls of screening the movements of its division. I think that these duties cannot always be clearly regulated according to the idea of an offensive or defensive screen; they will more often be of a mixed nature. As far as its strength will admit, the divisional cavalry will endeavour to carry out the task by pushing back, by fighting, the hostile reconnoitring patrols and detachments before these have succeeded in gaining observation. As it is more or less locally confined to its own front, and will certainly often have to do with an opponent of superior strength, it will, on the other hand, frequently be obliged to join battle for favourable localities dismounted, supported whenever possible by machine-guns and cyclists from the infantry. In situations where the divisional cavalry cannot undertake an offensive fight against the superiority of the enemy, and can find no _points d'appui_ in the terrain, it must try all the more to block the roads with patrols which will attack all hostile patrols with the utmost determination, and endeavour to capture their despatch-riders. The divisional cavalry must show the greatest boldness and judgment if it will carry out this task. The great importance of its rôle in the army here again becomes obvious. The army cavalry will only undertake an offensive screen when the army is advancing, and where the country does not afford suitable localities for the establishment of a defensive screen. Such a screen (defensive), which can eventually be pushed forward from one area to another, is without doubt, as is emphasised by the "Field Service Manual," of much more use than an offensive screen. Of great importance in a defensive screen is, first and foremost, the nature of the obstacles on which it is based. Watercourses and canals, which can only be crossed by bridges, form the best of these. Extensive woods, however, lend themselves easily to the purpose. They are doubtless, for cavalry patrols, a most unpleasant obstacle, as view is restricted in them, and an ambush may lurk behind every tree. In the campaign of 1870-71 the German cavalry patrols were, as far as I could ascertain, quite unable to penetrate into the wood of Orleans and that at Marchenoir. These woods, by their mere existence, formed an effective screen.