birds digest all they eat? . . . . . . . . . . . . . . . 64
40. Color, odor, and pleasant taste of fruits are
advertisements . . . . . . . . . . . . . . . . . . . . . 65
41. The meddlesome crow lends a hand . . . . . . . . . . . . . . 68
42. Ants distribute some kinds of seeds . . . . . . . . . . . . 69
43. Cattle carry away living plants and seeds . . . . . . . . . 70
44. Water-fowl and muskrats carry seeds in mud . . . . . . . . . 71
45. Why some seeds are sticky . . . . . . . . . . . . . . . . . 72
46. Three devices of Virginia knotweed . . . . . . . . . . . . . 73
47. Hooks rendered harmless till time of need . . . . . . . . . 74
48. Diversity of devices in the rose family for seed sowing . . 76
49. Grouse, fox, and dog carry burs . . . . . . . . . . . . . . 76
50. Seeds enough and to spare . . . . . . . . . . . . . . . . . 78

CHAPTER VIII.--MAN DISPERSES SEEDS AND PLANTS.

51. Burs stick to clothing . . . . . . . . . . . . . . . . . . . 80
52. Man takes plants westward, though a few migrate eastward . . 83

CHAPTER IX.--SOME REASONS FOR PLANT MIGRATION.

53. Plants are not charitable beings . . . . . . . . . . . . . . 84
54. Plants migrate to improve their condition . . . . . . . . . 85
55. Fruit grown in a new country is often fair . . . . . . . . . 85
56. Much remains to be discovered . . . . . . . . . . . . . . . 86

BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . . . . . . . 89

SEED DISPERSAL.

CHAPTER I.
HOW ANIMALS GET ABOUT.

1. Most of the larger animals move about freely.--When danger
threatens, the rabbit bounds away in long jumps, seeking protection
in a hollow tree, a log, or a hole in the ground. When food becomes
scarce, squirrels quickly shift to new regions. Coons, bears, skunks,
and porcupines move from one neighborhood to another. When the
thickets disappear and hunters abound, wild turkeys and partridges
retreat on foot or by wing. When the leaves fall and the cold winds
blow, wild geese leave the lakes in secluded northern homes, and with
their families, reared during the summer, go south to spend the winter.
Turtles swim from pond to pond or crawl from the water to the sand
bank, where they lay and cover their eggs. Fishes swim up or down
the creek with changing seasons, or seek deep or shallow water as
their needs require. Beetles and butterflies, when young, crawl about
for food and shelter, and when older use their wings in going long
di