The receipt of these instructions was not followed by any immediate change in GROUCHY's dispositions. He despatched no Cavalry force--not even a single Patrol--to watch any movements that might be attempted, or actually then in course of execution, by the Prussians, towards the Field on which the Emperor had intimated to him his intention of attacking the force under WELLINGTON; and hence it is almost needless to add, that he neglected to establish that close and active communication with the main Army which was so essentially important for the accomplishment of the object of the general plan of operations, and to which NAPOLEON had especially directed his attention in the before mentioned despatch. His sole aim seemed to be a direct advance upon Wavre; and this he carried into execution without at all detaching to, or in any way manoeuvring by, his left. On the contrary, upon arriving in person at the position occupied by EXCELMANS, he desired the latter to move to his right, and take post at Dion le Mont; and the ground thus vacated was shortly afterwards taken up by VALLIN's Light Cavalry Division. * * * * * At daybreak of the 18th of June, BÜLOW, in conformity with the Order which he had received during the previous night from BLÜCHER, quitted his position near Dion le Mont, to march through Wavre to St Lambert. This was the commencement of the important flank movement of the Prussians in support of the Anglo-Allied Army in position in front of Waterloo; and every measure of precaution was adopted with a view to its being carried into effect with certainty and safety. The sun had not yet risen when Major WITOWSKY was despatched with a Detachment of the 2nd Silesian Hussars, to Maransart, for the purpose of closely reconnoitring the Defiles of the Lasne, which had already been patrolled the evening before, and to observe the country in front of those Defiles, in the direction of the Enemy's position. Major FALKENHAUSEN, previously mentioned as having pushed a reconnaissance beyond Seroulx on the 17th, was now directed also to reconnoitre the Lasne. Scouring parties were sent out, which kept up the communication that had been opened the previous day with Lieutenant Colonel LEDEBUR at Mont St Guibert: the whole country between the Dyle and the Charleroi high road was carefully explored; and correct intelligence was continually sent to the rear concerning the French Army. By means of this vigilant look out, the Prussians secured the important advantage of retarding the communications between the French Emperor and his Marshal, since it compelled the bearer of despatches to pursue a very circuitous route. At half past nine o'clock, on the morning of the 18th, whilst BÜLOW's Corps was on the march to St Lambert, the following additional despatch was forwarded to General MÜFFLING:-- "Wavre, 18th June 1815, at half past nine o'clock.