Bluebird (_Sialia sialis_), war with a wren, 66-68; courtship of, 79; jealousy and a duel, 80-82, 91; arrival of, 158, 159, 160; imaginary rivals, 189-191; and downy woodpecker, 272; war with a great crested flycatcher, 274, 275; jealousy and courage of, 275; and English sparrow, 275, 292, 293; feeding a family of vireos, 313, 314; notes of, 79-82, 158, 159, 163; nest and eggs of, 15, 64, 66, 68, 79-82, 189, 191, 275. Blue-grass, 223, 227, 228, 234. Blue-grass region, the, 223-234. Bluets. _See_ Houstonia. Blue-weed. _See_ Bugloss, viper's. Bobolink (_Dolichonyx oryzivorus_), 188, 239; song of, 239; nest of, 188. Bob-white. _See_ Quail. Boneset, climbing, 31. Boswell, James, 251. Botany, the study of, 27, 28; a needed aid in, 31, 32. Bowlders, refusing to stay down, 100, 101. Brooks. _See_ Trout streams. Bugloss, viper's, _or_ blue-weed, 29, 30. Bullfrog, 255. Bumblebee, 14; visiting the closed gentian, 27 and note; drones, 269. Bunting, black-throated, _or_ dickcissel (_Spiza americana_), 239; song of, 239. Bunting, indigo. _See_ Indigo-bird. Bunting, snow, _or_ snowflake (_Plectrophenax nivalis_), 200. Calf, fear in the young, 195. Calypso, the orchid, 1, 2. Cambium layer, the, 158. Camp, repairing, 47, 52; rain in, 48; a cold night in, 52-54. Camping, in the southern Catskills, 33-60. Campion, bladder, 29. Canary, 96, 97, 191, 305. Cardinal (_Cardinalis cardinalis_), 239. Cardinal-flower, 11, 29. Carlyle, Thomas, a woman's opinion of, 108, 109; quotation from, 297. Catbird (_Galeoscoptes carolinensis_), 142; song of, 308. Cats, chipmunks and, 148-150; red squirrels and, 195. Catskills, mountaineering in the southern, 33-60; the rocks of, 34, 46, 47; the water of, 40. Cattle, backwoods, 58, 59. Cedar-bird, _or_ cedar waxwing (_Ampelis cedrorum_), 72, 200; nest and eggs of, 70, 72. Charming, the power of, 255-257. Chat, yellow-breasted (_Icteria virens_), 239. Chelone, _or_ turtle-head, 29. Cherry pits, 151, 152. Chewink, _or_ towhee (_Pipilo erythrophthalmus_), 14. Chickadee (_Parus atricapillus_), 121; young leaving the nest, 292, 293; family life continued after the nest is left, 293, 294; a fatal malady, 294; a male feeding his mate, 298; notes of, 293, 294; nest of, 70, 257, 258, 292, 293, 298, 299.