December 11th had been a day of joy in the allied camp, owing to the arrival of General Florencio Xatruch with the first contingent of Honduran troops;[XVII-40] but they were cut up in the attack of the 13th by Henningsen. This officer's success in extricating himself with so much loss to his opponents caused a panic among the allied leaders, and the breaking out anew of dissension. Belloso and his Salvadorans went back to Masaya, reporting the discomfiture of the army. Whether out of spite, or from ignorance of the state of affairs, the general ordered Cañas to return to Costa Rica, and Jerez to retreat to Masaya. The latter, as a subordinate, had to obey; but Cañas, having come to fight the filibusters, would not go back, and accompanied Jerez to Masaya. Thus was Rivas evacuated by the allies, and reoccupied by Walker without firing a shot. The lake steamers were of great advantage to Walker for the quick transportation of men and supplies, and on the other hand, made it necessary that the allied chiefs should have strong garrisons in Granada and Masaya, preventing a movement on La Vírgen and Rivas. The president of Costa Rica determined to deprive Walker of those facilities. To this end he despatched his brother, General José Joaquin Mora, with troops to the confluence of the San Cárlos and San Juan rivers, who reached it on the 19th of December, and then going down in canoes to San Juan del Norte, without encountering much resistance, captured on the 24th four steamers.[XVII-41] They then went up the San Juan with the steamers, two of which were left at the junction with the Sarapiquí, and on the 28th took the Castillo Viejo with the steamboat _Vírgen_, laden with artillery, rifles, and ammunition. They next possessed themselves of Fort San Cárlos, and soon after of the steamboat of the same name, which had incautiously approached the fort. All this being accomplished, Mora was placed in communication with the allied forces of Granada, and left Walker without means of transportation by water, or to communicate with the northern sea-coast. Had the allies acted with reasonable promptness, both on land and water, Walker's end would have been a matter of only a few days. But it was retarded by their lack of union and generalship.[XVII-42] His situation was now critical. Desertions, which were frequent, sickness, and scarcity of food, daily decreased his force. For all that, he resisted in Rivas several assaults from both the land and lake till the 23d of February, and struck some heavy blows to the besiegers in San Jorge.[XVII-43] [Sidenote: THE INVADERS BESIEGED.]