Part 27

Sparrow, song, song flight, 37; nesting, 54; singing, 85, 86.

Sparrow, vesper, nesting, 80-84; its names, 82; appearance and habits, 82, 83; courted by a skylark, 83.

Species, origin of, an insoluble problem, 167-69, 199.

Spider, trap-door, 132-43.

Spiders, 12, 23; genius of, 136.

Spider-webs, rainbows in, 13, 14.

Squirrel, gray, caught by a weasel, 178.

Squirrel, red, chased by a weasel, 178.

Strawberry-vines, wild, 212-14.

Struggle, 203, 204.

Sunrise, 197, 198.

Survival of the fit, 201, 203.

Swallow, bank, 78.

Swallow, barn, 71; parental anxiety, 76, 77; notes, 76, 77; pleasing qualities, 77, 78.

Swallow, cliff, 77.

Swallow, tree, 78.

Swallows, feeding, 15, 16; hibernation, 78.

Swift, chimney, 36.

Sycamore, autumn color, 3.

Taft, William Howard, 105.

Telepathy, 155.

Thistle, Canada, 202.

Thorns, the use of, 143-48.

Thrasher, brown, 67, 68.

Thrush, Alaska hermit, 129.

Thrush, hermit, song, 87.

Thrush, olive-backed, 30.

Thrush, Wilson's. See Veery.