Another place that never failed to attract us was a small lagoon flanked by forest on two sides, and by prairie on the others. This region was the resort of many birds. Flocks of Brazilian cardinals (_Paroaria_) numbering up to thirty individuals congregated in the bushes, their flaming red heads reminding one of clusters of brilliant flowers. We discovered a nest of the species, a shallow affair of grass stems, placed in the end of a branch twenty feet above the ground; in it were two eggs resembling those of the English sparrow. Small black-and-white flycatchers (_Fluvicola_) found the lagoon a most attractive spot. Their pear-shaped bag nests of interwoven grasses and feathers were scattered about in the overhanging bushes and also fastened to the stems of aquatic plants, sometimes but a foot above the water. There were also numbers of grebes, coots, and gallinules, and occasionally a pair of beautiful Brazilian teals visited the quiet, secluded body of water. Night-herons kept well to the tops of the taller trees; and everglade kites flew gracefully and swiftly overhead, usually singly, and rarely in pairs. We heard the weird call of chachalacas almost daily, but these birds had been persecuted by native hunters until they had acquired enough wisdom to avoid hunters and human beings in general. In one wet strip of woods we found limpkins in limited numbers. They did not seem to ever come out into the open country. There was not time to study the frogs, fish, and small snakes that we saw occasionally; nor to more than admire the myriads of flowers and curious plants growing on all sides. There was, however, another naturalist (José Steinbach) working in the locality at the time of our visit, and fortunately he devoted practically all his energies to the study of the very things we had to omit, so between both expeditions the fauna and flora were pretty well covered. Many of the available trees were burdened with the huge stick nests of the leñateros (_Synallaxis_). Some of the structures measured six feet long and two feet through. They were built of thorny twigs, at the ends of branches. A heap of material is first placed at the very tip of a limb, and as the weight causes it to sag downward, more sticks are added until the huge mass hangs suspended in a vertical position. The thorns cause the whole affair to hold together so well that opossums and other predatory animals find it impossible to burrow their way through the walls to the interior cavity where the four or five white eggs, or the young birds, are cleverly concealed in a downy cup. There is usually a second chamber near the top of the nest; this is the male bird’s night quarters while his mate is incubating or brooding in the lower story.