f, 39;
lark-like in color and markings, 40;
wooed by a skylark, 40;
low degree of variability in, 259.

Spring, the real beginning of, 51, 52.

Squirrel, gray, 75, 133.

Squirrel, red,
nesting-material of, 20;
a stupid, 125;
and chestnuts, 132;
and maple sap, 132;
and green apples and pears, 133, 155, 251.

Squirrels,
and chestnut burs, 3;
their knowledge of nuts, 133;
smelling with the whole body, 133.

Starling, red-shouldered, _or_ red-winged blackbird
(_Agelaius phoeniceus_), song of, 34.

Stevenson, Robert Louis, on the English blackbird's songs, 45.

Sumac, fruit of, 254.

Swallow, cliff (_Petrochelidon lunifrons_), nesting of, 155, 157.

Swallows, 93.

Swift, chimney (_Chaetura pelagica_),
change of nesting-site, 8;
getting nesting-material, 8, 9;
in the chimney, 9;
a creature of the air, 9, 10;
spring and fall congregations in large chimneys, 10-13;
drumming in chimney, 183.

Swimming, 78, 79.

Sycamore, fruit of, 251.

Tanager, scarlet (_Piranga erythromelas_),
nesting in a cherry tree, 6, 7.

Teaching among animals, 83-94, 233, 234.

Telepathy, 96-98.

Terns, 139.

Thoreau, Henry D., his "night-warbler," 42, 153, 195, 203.

Thrush, hermit (_Hylocichla guttata pallasii_),
with an impediment, 116.

Thrush,
song, in the Trossachs, 46;
and wooden eggs, 227.

Thrush, Wilson's. _See_ Veery.

Thrush, wood (_Hylocichla mustelina_),
nest of, 5;
a "singing-school," 94;
nest-building of, 113, 114, 155, 156;
ways of, 113, 114;
song contest of, 114, 115.

Toad, going into the ground, 49.

Towhee. _See_ Chewink.

_Training of Wild Animals, The_, by Frank C. Bostock, 239-242.

Traps, the fear of, 89.

Tumble-bug, 26.

Turkey, 75, 214.

Van Dyke, Henry, his poem on the song sparrow, 31.

Variation, 73;
a less active principle now than formerly, 120;
various degrees of, 120, 121;
causes of, 121.

Veery, or Wilson's thrush (_Hylocichla fuscescens_),
song of, 84, 85.

Wallace, Alfred Russel, 87;
on mimicry, 249, 251.

Warbler, black and white creeping (_Mniotilta varia_),
nest and egg of, 111.

Warbler, grasshopper, 227.

Warbler, yellow (_Dendroioa aestiva_),
and cowbird's egg, 80, 156, 157, 229.

Ward, Lester F., his _Pure Sociology_, 112.

Wasps, s