On leaving Sontuli, the road led over mountain pastures and through woods of the evergreen oak draped from top to bottom with the grey moss-like Tillandsia, which hung in long festoons from every branch, and was wound around the trunks, like garlands, by the wind: the larger masses, waving in the breeze, hung down for four or five feet below the branches. The small birds build in them, and they form excellent hiding-places for their nests, where they are tolerably secure from the attacks of their numerous enemies. I had often, when in the tropics, to notice the great sagacity or instinct of the small birds in choosing places for their nests. So many animals--monkeys, wild-cats, raccoons, opossums, and tree-rats--are constantly prowling about, looking out for eggs and young birds, that, unless placed with great care, their progeny would almost certainly be destroyed. The different species of Oropendula or Orioles (Icteridae) of tropical America choose high, smooth-barked trees, standing apart from others, from which to hang their pendulous nests. Monkeys cannot get at them from the tops of other trees, and any predatory mammal attempting to ascend the smooth trunks would be greatly exposed to the attacks of the birds, armed, as they are, with strong sharp-pointed beaks. Several other birds in the forest suspend their nests from the small but tough air roots that hang down from the epiphytes growing on the branches, where they often look like a natural bunch of moss growing on them. The various prickly bushes are much chosen, especially the bull's-horn thorn, which I have already described. Many birds hang their nests from the extremities of the branches, and a safer place could hardly be chosen, as with the sharp thorns and the stinging ants that inhabit them no mammal would, I think, dare to attempt the ascent of the tree. Stinging ants are not the only insects whose assistance birds secure by building near their nests. A small parrot builds constantly on the plains in a hole made in the nests of the termites, and a species of fly-catcher makes its nest alongside of that of one of the wasps. On the savannahs, between Acoyapo and Nancital, there is a shrub with sharp curved prickles, called Viena paraca (come here) by the Spaniards, because it is difficult to extricate oneself from its hold when the dress is caught, for as one part is cleared another will be entangled. A yellow and brown flycatcher builds its nest in these bushes, and generally places it alongside that of a banded wasp, so that with the prickles and the wasps it is well guarded. I witnessed, however, the death of one of the birds from the very means it had chosen for the protection of its young. Darting hurriedly out of its domed nest as we were passing, it was caught just under its bill by one of the curved hook-like thorns, and in trying to extricate itself got further entangled. Its fluttering disturbed the wasps, who flew down upon it, and in less than a