Again: it will be remembered that no sooner had Melas learned that the Army of Reserve was marching on Milan than he sent orders to General Elsnitz to abandon the Var and to General Ott to raise the siege of Genoa. Even the mere knowledge of Bonaparte's destination, before the movement on Milan had actually been completed, was of itself sufficient to cause Melas to change immediately his entire plan of campaign. Had not Masséna, at the time, been just on the point of giving up Genoa, General Ott would not have delayed there two or three days to await the capitulation. In fact, had Masséna known of the exact state of affairs, he doubtless would have held out a day or two longer, and saved himself the humiliation of a surrender. Even without a battle, the concentration of the French forces between Milan and Placentia would, in a short time, have set free Masséna's soldiers; for Melas would then have been obliged to concentrate and fight, in order to recover his communications and connect with his base of supplies. Bonaparte saw clearly this fact. Though he did not know how long Masséna could hold out at Genoa, he realized that matters there were rapidly approaching a crisis, and that it was of the utmost importance that the Army of Reserve should reach Milan at the earliest possible moment. He realized that upon the direction given his columns and upon the rapidity of their movements depended the fate of Suchet on the Var and of Masséna at Genoa. Other reasons, too, deterred Bonaparte from marching the Army of Reserve through Switzerland. In this rough and mountainous country, supplies could not be easily obtained. Especially was this true of the St. Gothard route, which had been overrun by the French during the two previous years. Besides, this route was reserved for Moncey's corps, which, of itself, would tax to the utmost the resources of the country. Moreover, this road, a mere bridle path in places, passes through narrow defiles and across lofty and rugged mountains. Evidently a large army issuing into Italy by this route would be so stretched out that the advance divisions could be defeated before the rear divisions could re-enforce them. The Simplon route was shorter than the St. Gothard route, but the difficulties to be overcome on each were of the same character. Inasmuch, however, as Lake Maggiore lies between these two routes, it will be observed that, had Bonaparte advanced into Italy by way of the Simplon, while Moncey marched by way of the St. Gothard, Melas might have assembled a strong force at the foot of the lake, and, from his central position, have thrown superior numbers against each French column in succession. In this way he might have defeated both in detail before they could have united at Milan.