Nature,
an endless experimenter, 24, 139;
prodigality of, 27;
like a hunter, 27;
bound to hit the mark, 28;
the tendency to sentimentalize, 108;
reaches her ends by devious paths, 110;
the thinking of, 152;
literary treatment of, 191-208;
the interpretation of, 196-201, 203-205;
wisdom of, 220.

Newts, migrations of, 219.

Nightingale,
carrying nest, 15, 16;
song of, 35;
song of a caged bird, 35;
a song contest, 115.

_North American Review_, an article in the, 61.

Nuthatch, 162.

Nuts, protective colors of, 251, 252.

Observing, rarity of accurate, 107, 108, 238.

Olaus, his fox and crab story, 106.

Oriole, Baltimore (_Icterus galbula_),
a published account of a nest, 61-63;
Scott's experiment with young, 68;
its nest a marvel of blind skill, 110;
its use of strings in nest-building, 247;
an incredible story of, 248;
variability of, 259, 260;
song of, 259, 260;
destructive in vineyards, 261.

Oriole, orchard (_Icterus spurius_), 260.

Osprey, 137. _See also_ Fish hawk.

Ostrich, 134, 135.

Ousel, water, or dipper, 73.

Oven-bird (_Seiurus aurocapillus_),
walk of, 40;
ordinary song of, 40, 41;
flight song of, 41, 42.

Peacock, strutting before a crow, 217.

Peckham, George W. and Elizabeth G.,
their work on the solitary wasps, 116.

Pelicans, driving fish, 216.

Phoebe-bird (_Sayornis phoebe_),
nesting-habits of, 5, 157, 158;
nest-building of, 112;
cowbird's egg in nest of, 157;
an instance of stupidity, 168, 169.

Pigeon, passenger, or wild pigeon (_Ectopistes migratorius_),
flocks of, 96, 97.

Pike, 127.

Plants, intelligence of, 128, 129.

Plover, ring, rejecting counterfeit eggs, 227, 228.

Poison, fear of, 140.

Poisoning among animals, 105, 106.

Porcupine,
its lack of wit, 3, 186;
an encounter with a, 242-244;
easily killed, 244;
stories of rolling into a ball, 244, 245;
C. G. D. Roberts on, 245, 246.

Prairie-dogs, their fear of weeds and grass, 189.

Protective coloration, 139, 140.

Quail, or bob-white (_Colinus virginianus_), nests of, 6.

Rabbit,
nest of, 7;
intelligence of, 7;
pursued by a mink or weasel, 7, 8;
pursued by a fox, 8;
imitating a monkey, 66.

Rabbit, jack, 184;
running in a furrow, 213.

Ra