Despite the recent draining of the Stamboul camp by the despatch of a large force to Salonika, there are still some 45,000 men in and around the capital. These, with the exception of the Sultan’s guard of about 15,000 men, have been distributed along the chain of forts extending from Roumelie Kavak to the Golden Horn. The telegraph is kept busily at work summoning troops from all parts of the Empire. 15,000 men from the Adrianople garrison are expected to arrive here to-night. The Russian Ambassador is said to be ill. He has not left the Embassy in the Grand Rue de Pera for now almost a week, and refuses to receive any one. Even his French colleague found the door closed to him yesterday. [Illustration: RUSSIAN INFANTRY LANDING AT VARNA. ] CONSTANTINOPLE, _April 19_. A Russian force, variously computed at from 50,000 to 70,000 men, occupied Varna this morning. There was some smart resistance, but the comparatively small Bulgarian force was powerless against the heavy metal of the Russian fleet, and after an hour’s fighting was compelled to abandon the position. Coincident with the receipt of this news is the delivery of a note by the Russian Ambassador—suddenly restored to health—to the Minister for Foreign Affairs, setting forth that, as a result of the extraordinary and uncalled-for position taken up by Austria, the Czar’s Government feels the necessity of acquiring a material guarantee for the maintenance of peace, and will therefore effect a peaceful occupation of Bourgas and Varna with that end in view. RUSSIAN MOVEMENT UPON THE AUSTRIAN FRONTIER. MOBILISATION OF GERMAN ARMY CORPS—WILD EXCITEMENT IN BERLIN. (_By Telegraph from our Special Correspondent, Mr. Charles Lowe._) BERLIN, _April 21_ (8.50 P.M.). Never since the fateful days of July 1870 has so much excitement been caused here as by the news—which now seems to be beyond all doubt—that Russia, having received an evasive, or, as other telegrams put it, a flatly negative reply to her peremptory demand for the immediate evacuation of Belgrade by the Austrians, has already begun to move down immense masses of troops towards her south-western frontier; and it is even rumoured that a division of cavalry has suddenly made its appearance near the border, on the Warsaw-Cracow road, at a place called Xiaswielki. This is a grave situation, indeed, as alarming as it is sudden. The Unter den Linden, which is a perfect Babel with the bawling voices of the newsvendors, is rapidly filling with crowds rushing hither, as to the main channel of intelligence, from all parts of the city, and the Foreign Office in the Wilhelm-Strasse is besieged by a huge throng clamouring to hear the truth.