Throughout my lifetime I have been by turns amazed, entertained and instructed by the marvelous intelligence and mechanical skill of small mammals in constructing burrows, and of certain birds in the construction of their nests. Today the hanging nest of the Baltimore oriole is to me an even greater wonder than it was when I first saw one over sixty years ago. Even today the mechanical skill involved in its construction is beyond my comprehension. My dull brain can not figure out the processes by which the bird begins to weave its hanging purse at the tip end of the most unstable of all earthly building sites,--a down-hanging elm-tree branch that is swayed to and fro by every passing breeze. The situation is so "impossible" that thus far no moving picture artist has ever caught and recorded the process. Take in your hand a standard oriole nest, and examine it thoroughly. First you will note that it is very strong, and thoroughly durable. It can stand the lashings of the fiercest gales that visit our storm-beaten shore. How long would it take a man to unravel that nest, wisp by wisp, and resolve it into a loose pile of materials? Certainly not less than an entire day. Do you think that even your skilful fingers,-- unassisted by needles,--could in two days, or in three, weave of those same materials a nest like that, that would function as did the original? I doubt it. The materials consist of long strips of the thin inner bark of trees, short strings, and tiny grass stems that are long, pliable and tough. Who taught the oriole how to find and to weave those rare and hard-to-find materials? And how did it manage all that weaving with its beak only? Let the wise ones answer, if they can; for I confess that I can not! Down in Venezuela, in the delta of the Orinoco River, and elsewhere, lives a black and yellow bird called the giant cacique (pronounced cay-seek'), which as a nest-builder far surpasses our oriole. Often the cacique's hanging nest is from four to six feet long. The oriole builds to escape the red squirrels, but the cacique has to reckon with the prehensile-tailed monkeys. Sometimes a dozen caciques will hang their nests in close proximity to a wasps' nest, as if for additional protection. A cacique's nest hangs like a grass rope, with a commodious purse at its lower end, entered by a narrow perpendicular slit a foot or so above the terminal facilities. It is impossible to achieve one of these nests without either shooting off the limb to which it hangs, or felling the tree. If it hangs low enough a charge of coarse shot usually will cut the limb, but if high, cutting it down with a rifle bullet is a more serious matter. [Illustration with caption: HANGING NEST OF THE BALTIMORE ORIOLE (From the "American Natural History")] [Illustration with caption: GREAT HANGING NESTS OF THE CRESTED CACIQUE As seen in the delta of the Orinoco Rover, Venezuela.]