Mammalian life was scarce, but considering the short time available, a comparatively representative collection was made, including specimens of a small gray wolf (_Cerdocyon_), which roamed singly and in pairs in the country bordering the Paraguay River. A few rabbits and opossums visited the mandioc-fields at night to feed upon the succulent tubers. We had abundant opportunities to observe the rural populace in the vicinity of Trinidad. They are of a rather unambitious type, and seemed contented only when taking their noonday nap or _siesta_, or while drinking _maté_. The general language of Paraguay is Guaraní, although Spanish is used by the upper classes. “Yerba maté” is the modern name for the _caá guazú_ of the Guaraní. It is applied to the dried leaves of a species of South American holly (_Ilex_) growing abundantly in parts of Brazil, Argentina, and Paraguay. The tree is very bushy and beautiful, and remains green the year around; the leaves are small, and those of a light-green color make the best quality of tea. Several methods are employed in gathering the leaves: one is to cut down the branches, pile them into huge stacks, and apply heat for about twenty-four hours, when they are dry and ready for the next stage of manufacture, consisting of pulverization. The heating and drying process is known as torrefaction. In preparing the beverage a quantity of the powdered leaves, and sometimes sugar, also, are placed in a small, hollowed gourd, and the container is then filled with boiling water. The liquor is taken through a metal tube called _bombilla_, with a hollow, spoon-shaped expansion filled with small holes on the end that is placed in the gourd. It is customary to refill the container with water many times before recharging it with leaves, and to pass it around among all the members of a family and any guests who chance to be present. Everybody drinks in turn from the same maté and tube. A kettle of boiling water is kept on a charcoal brazier near at hand. Some of the containers or matés are very elaborate affairs, made of pure silver and elegantly carved or chased. The amount of _yerba maté_ consumed annually is enormous. It is estimated that no less than ten millions of persons in South America indulge in the habit. In Chile the annual consumption per capita is about one hundred and twelve pounds; in Paraguay thirty-four pounds, and in the Argentine twenty pounds. Quantities of it are also exported, principally to Holland. Some years the supply falls short of the demand, but plantations have added very materially to the available wild growth.