Caveman, what he learned from his fellow animals, 228 Central America, a good place to look for Flamingoes, 166 Chipmunks, work and play in Chipmunkville, 131; why they have large feet for such little people, 132; inside the Chipmunk's home, 132; why they have several front doors, 133; how they spend the winter, 218 Clouds, how dust helps make them, 56; and shape them, 57 Colorado, once the home of prehistoric monsters, 27 Corn, how the "rag babies" tell the fortune of the seed, 199 Crabs, water farmers who help make land, 140 Crayfish, their habits and their service in helping get land ready for the farmer, 140 Crustaceans, their relation to insects, 143 Cuvier, Baron, the famous paleontologist, and his adventure with a "monster," 34 Dandelions, flying machines of, 51 Darwin, Charles, on the importance of earthworms in the history of human civilization, 75; what he said about the intelligence of roots and why he said it (the whole chapter is about that), 186; how he taught roots to write their autobiographies, 190 Deserts, plant pioneers in, 8; rich in plant food, 59; how irrigation transforms them, 72 Dormice, their Thanksgiving dinners and their long winter naps, 204, 217 Duck-billed Mole, the Animal X that lays eggs like a bird and yet suckles its young like a pussy-cat, 144 Dust, how it helps the rain come down, 56 Earthworms, great importance of their work in pulverizing and fertilizing the soil, 75; their habits and remarkable intelligence, 75; how the great sea and the little earthworms work together, 242 East Indies, home of some of the Hornbills, 169 Electricity, how it helps in the shaping of the clouds, 57 Elephants, their ancestors among the prehistoric monsters, 27; elephants as ploughmen, 28 Fabre, Henri, his study of the Mason Bee and how his schoolboys helped him, 108 Farms, abandoned, how Nature restores them, 16 Fish, monster fish of other days, 23 Flamingoes, habits of some feathered farmers with queer noses, 162 Florida, one place where you may find flamingoes, 166 Fox, home life and habits, 128 Frost, Jack, how he helps convert rock into soil, 43; how he makes stones "walk" and in other ways co-operates with the river mills in making soil, 60 Geese, their relation to the flamingoes, 166 Groundhog. (See Woodchuck.) Hamster, a four-footed farmer who uses a threshing-machine, 210 Hedgehogs, why they are so unpopular as food, 121; their homes and how they do their ploughing, 122; pictures of baby hedgehogs, 216, 217; why they go into winter quarters, 216, 218 Hibernation, "The Autumn Stores and the Long Winter Night," 204 Hornbills, why Mr. Hornbill shuts his wife up in their home in a hollow tree, 169 Hungary, home of the field rat, a farmer who stores grain for the winter, 212