Snakes, and the power of fascination, 16. Solitude, its effect on individuality, 118, 119. Sparrow, bush, or field sparrow (_Spizella pusilla_), nest of, 259. Sparrow, chipping (_Spizella socialis_), nest of, 142, 143, 259, 154; an unusual song of, 259. Sparrow, English (_Passer domesticus_), singing like a canary, 68, 257; eggs of, 120; a case of blind instinct in, 160. Sparrow, song (_Melospiza cinerea melodia_), a city girl's impression of its song, 31; a talented singer, 45; the "Hermit's" story, 93, 94; variability of, 259. Sparrow, vesper (_Pooecetes gramineus_), flight song of, 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 (_Chætura 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 æstiva_), and cowbird's egg, 80, 156, 157, 229.