The Marquis of Bucarelli, governor of Buenos Ayres, wishing to go personally, accompanied by the best troops of Europe which he could collect in that capital, to execute the orders of his sovereign relative to the missions, which were repugnant to the feelings of the Indians, wrote, before he commenced his march, to all the vicars to send to him the chief (_cacique_) and head magistrate of each mission, in order that he might communicate to them advices from his Majesty. On their arrival at Buenos Ayres he unjustly retained them as hostages, with a view of obviating any difficulty that might arise. In Yapegú, which is the first mission, was presented to him the celebrated chief, Nicolau, who in Europe passed for the sovereign of the Guaranitic republic, and who was not able to proceed in the train of the others, in consequence of the infirmities of old age, being then seventy. The Europeans and their descendants began to frequent the missions, and the Indians to have mutual relations with them, and to learn from them many of the most familiar words, also some relaxation from the more correct morals and manners of the Jesuits. The population, in consequence, soon began to diminish, as well as the neatness and cleanliness of their houses and temples. MOUNTAINS.--In the northern part there is the serra of Maracaju, which is of trifling altitude; and the Lambara, in the vicinity of the capital, also not of remarkable elevation, although it exceeds in height all those that encompass it. The mineralogy consists of _gesso_, or plaster, limestone, granite, and marble. RIVERS AND LAKES.--Besides the three great rivers that limit this province, there are many others which water the interior, and some of them navigable for a considerable distance. The Gualeguay, which has a course of more than one hundred and forty miles, empties itself into the Uruguay, a few leagues above the Negro, after having watered a level country, rich in cattle, corn, and fruit trees. The Mirinay, which also runs into the Uruguay, fifty miles below the Ibicui, is considerable, and runs through an extensive country, stocked with large cattle. The Taquary, seventy miles long, empties itself also into the Uruguay, ninety miles below the preceding. The Jaguare, rising in the Serra Maracaju, runs into the Paranna, twelve leagues below the Setequedas (Seven Falls). According to a map of the country, which does not appear a bad one, the Acarahy is the first considerable river which enters the Paranna by the right bank, seventy miles below the Setequedas. The Tibiquary, which is considerable, disembogues into the Paraguay ninety miles above the confluence of the Paranna. The Cannabé, after a course of one hundred miles, enters the Paraguay fifty miles north of the Tibiquary.