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IOWA ACADEMY OP SCIENCE 
suspended by the top from a long drooping branch or trailing liana, usually over 
a stream, from four to fifteen feet from the water. The greatest diameter is a 
little below the middle, and at this point the cavity is situated, which is en- 
tered by a small hole. The nest is composed of coarse fibrous material and cov- 
ered over the outside with dry leaves, leaf stems, and large twigs, some of the 
last a foot or more in length. The whole affair in almost every detail so closely 
resembles a small mass of debris left by a retreating fiood, as to deceive the keen- 
est enemy. Furthermore, the location assists greatly in the disguise, the nest 
appearing to be but one among thousands of such masses entangled in the vege- 
tation overhanging the stream. Add to this the difficulty any reptile or mammal 
would experience in reaching it, even were its nature known, and we have a 
most striking example of protective adaptation. 
Todirostrum cinereum and some other Tyrannidae make nests of precisely the 
same style as that of OnycJiorJiyncJius. That of T. cinereum is much less fre- 
quently built over a stream and is composed of finer material, often with so 
much cottony substance interwoven as to give it the appearance of a colony of 
“tent-caterpillars.” 
The nests of two other small Flycatchers, Todirostrum schistaceiceps and On- 
costoma cinereigulare, are also suspended by the top from small branches and 
entered by a hole at the side, but are somewhat pear-shaped. They are built 
but two or three feet from the ground, and if they are as inconspicuous to the 
reptilian as to the human observer, they are comparatively safe. 
Rhynchocyclus is a genus of small Flycatchers of obscure coloring and ordi- 
nary habits, noteworthy only for their curious nests, which are, perhaps, among 
the most remarkable examples of protective adaptation known. The nest of R. 
cinereiceps is built from ten to thirty feet above the ground, or water, as it 
frequently overhangs a stream. In shape it resembles an old shoe, or rather 
moccasin, suspended by the top with the entrance at the toe, and a harrow 
passage leading over the instep to the heel, where the main cavity is situated. 
It is composed of some kind of aerial roots — long, fine, black fibres resembling 
horse hair. It usually hangs from a long slender branch of one of those myrme- 
cophilous Acacias, whose stout double spines are hollow and inhabited by ants. 
The thorns are very numerous and the ants are extremely irritable and armed 
with formidable stings, equal in effectiveness to that of the bumble bee. The 
thorns alone would make the ascent of the tree by an animal of any size very 
difficult, but the presence of the ants renders it absolutely impossible. But this 
is not all. A species of hornet frequently makes its nest, a large conical or 
oval structure, in the same tree, and the nest of the bird and that of the insects 
may often be found within three or four feet of each other. The protection, how- 
ever, is not always so complete. A curious variation of the situation occurs 
when a tree with leaves closely resembling those of the Acacia is selected, and 
the nest is placed beside that of a species of ant, which at first sight would 
probably be mistaken for a hornet’s nest, so similar are the two in appearance. 
The nest of the Beardless Flycatcher, Gamptostoma imberde, is built in a 
small species of palmetto, in the upper angle formed by the juncture of a leaf- 
stem with the trunk. The trunk is very shaggy with the frayed margins of the 
fibrous sheathes, and the nest can be reached without difficulty by any climbing 
animal. The danger from such enemies, however, is greatly reduced by the 
structure and material of the nest. Except for the soft cottony lining it is 
composed entirely of fibres obtained from the trunk of the palm, ’which are deftly 
