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Mar., 1910 EFFECT OF ENEMIES ON NESTING HABITS OF HONDURAS BIRDS 55 excavated by the birds, except in those curious instances where the nest of a species of termite or "white ant" is used for this purpose. These nests are conical to nearly spherical in form, and from a few inches in diameter to the size of a barrel. They are commonly built on large branches some distance from the ground. In these structures, which are composed mainly of fine particles of wood cemented to- gether to form the walls of small, intricately winding passages, the fwo trogons, T. massena and T. melanocephalus, excavate holes for their nests. - The hole is begun near the bottom and leads upward to about the center of the cone, where it expands into a large chamber. The birds are ab- solutely dependent on the insects for their nesting sites, which are remarkably safe from the attack of enemies. Without some such for- tunate means of securing a rapid increase it is difficult to see how birds so feeble and of such low intelligence as these trogons could long survive. The nest of the same species of termite also furnishes homes occasionally for certain par- rots and apparently always the Paroquet, Co,rufus azlec, tho these species excavate from the top in- stead of the bottom of the nest, and it is doubtful whether they do not sometimes occupy holes made in the termite's nests by other animals. Most nests of the third type, such as those of the I&?eonidae and species of ]clerus, require no special mention. Tho not precisely of this type, we may place here the won- derful nests of the Oropendolas, Gymnoslinops and allied genera. Perhaps no birds' nests of tropical America are better known than these; it is, therefore, sufficient to say that probably they are absolute- ly untroubled by enemies if we ex- cept the parasitic Rice Grackle, Cassidix. Manikins of the genera A/Zanacus and lrYpra make small, shallow nests of extremely slight structure, / I Fig. 17. NESTS OF liUMMINGBIRDS, PHAETHORNIS ADOLPHI ON TI-IE LEFT, AND P. LOIVGIROSTRIS ON TliE RIGlIT and in the case of /?. ntenlalt's several dry leaves are hung loosely on the outside, which serves as a very effectual disguise. In both instances the nest is usually sus- pended near the end of a long, slender branch, inaccessible to most _reptiles. Two hummingbirds of the genus t?gaet?ornis suspend their nest from the