Picture Library; 17: © Tom Bean/Corbis; 19: Martin H. Simon/Corbis;
20: Bill Ross/Corbis; 22: Panoramic Images/Getty Images;
23: © Spectrum Colour Library/Heritage-Images; 24: (left) Alfredo
Maiquez/Lonely Planet Images, (right) Encyclop.dia Britannica, Inc.;
25: Keren Su/Stone; 26: (left) Keren Su/Corbis, (right) Judie
Anderson/EB Inc.; 27: Marlen Raabe/Corbis; 28: (left) Alvis Upitis—
The Image Bank/Getty Images, (right) Jacqui Hurst/Corbis;
29: © Chris Rainier—Corbis; 31: (top) Sarah J.H. Hubbard/Lonely
Planet Images, (bottom) Vieira de Queiroz—TYBA/Agencia
Fotografica; 32: Robert Caputo—Aurora/Getty Images; 33: Jose B.
Ruiz/Nature Picture Library; 34: (top) David Burnett—Contact Press
Images/PictureQuest, (bottom) Sylvain Grandadam; 35: © Ron
Sachs/Corbis; 36: © Corbis; 37: Tom Hanson—CP/AP; 38: The
Granger Collection, New York; 39: Nicole Duplaix—National
Geographic/Getty Images; 40: (left) age fotostock/SuperStock, (right)
Hulton-Deutsch Collection/Corbis; 41: © Corbis; 42: (left) Ron
Vesely/Getty Images, (right) G. Buttner—Naturbild/Photo Researchers,
Inc.; 43: Courtesy of Peace Corps; 44: © Reuters/Corbis; 45: Grant
Heilman Photography; 46: Walter Rawlings—Robert HardingWorld
Imagery/Getty Images; 47: (left) JoshWestrich—zefa/Corbis, (right)
© Darrell Gulin/Corbis; 48: Hulton Archive/Getty Images; 49: Judie
Anderson/EB Inc.; 50: © Allsport UK/Getty Images; 51: Richard
300 Credits BRITANNICA STUDENT ENCYCLOPEDIA
Nowitz—National Geographic/Getty Images; 52: (left) Encyclop.dia
Britannica, Inc., (right) Galen Rowell/Corbis; 53: © Lester V.
Bergman/Corbis; 54: Stock Montage—Hulton Archive/Getty Images;
56: Martin Rogers/Stone; 57: (top) age fotostock/SuperStock, (bottom)
Joseph Sohm—Visions Of America, LLC/PictureQuest; 58: (left)
© Tania Midgley/Corbis, (right) Scott Bauer—ARS/USDA; 59: Bob
Child/AP; 60: Judie Anderson/EB Inc.; 61: Gianni Dagli Orti/Corbis;
62: Sadayuki Mikami—Department of Defense (DOD)/Time Life
Pictures/Getty Images; 63: The Granger Collection, New York;
64: Frans Lanting/Corbis; 65: (top) © Robert Frerck/Stone, (bottom)
JeremyWoodhouse—Digital Vision/Getty Images; 66: © Rubberball
Productions/Getty Images; 67: A. Dagli Orti/DeA Picture Library;
68: David Frazier—Stone/Getty Images; 69: © Torleif
Svensson/Corbis; 70: Lester Lefkowitz—Photographer’s Choice/Getty
Images; 72: (left) Shostal Associates, (right) Penny Tweedie—
Stone/Getty Images; 73: Erich Lessing/Art Resource, New York;
74: (left) M. Mattson/Shostal Associates, (right) The Granger
Collection, New York; 75: Tom Bean/Corbis; 76: David Adame/AP;
77: Alinari Archives/Corbis; 78: Encyclop.dia Britannica, Inc.;
79: (left) Lawrence Migdale/Photo Researchers, Inc., (right) Kristine A.
Strom; 80: Library of Congress,Washington D.C.; 81: (inset) Library
of Congress,Washington D.C.; 82: (top) © Glen Allison/Getty Images,
(bottom) © Corbis; 83: Nick Garbutt/Nature Picture Library;
84: © GaryW. Carter/Corbis; 85: © Kapoor Baldev—Sygma/Corbis;
86: (left) AP, (right) Tom Bean/Corbis; 87: © Phil Schermeister/Corbis;
88: Library of Congress,Washington D.C.; 89: The Granger
Collection, New York; 90: © Robert & Linda Mitchell; 91: (left and
right) The Granger Collection, New York; 93: Encyclop.dia
Britannica, Inc.; 94: Robert Arnold—Taxi/Getty Images; 95: (top) Pete
Oxford/Nature Picture Library, (bottom) Tierbild Okapia/Photo
Researchers, Inc.; 96: Encyclop.dia Britannica, Inc.; 97: Jon Riley—
Stone/Getty Images; 100: (left) Tom McHugh/Photo Researchers, Inc.,
(right) Grant Heilman Photography; 101: Eliot Young, Southwest
Research Institute; NASA’s Planetary Astronomy Program;
102: Library of Congress,Washington D.C.; 103: James
Cavallini/Photo Researchers, Inc.; 104: MPI/Getty Images; 106: David
Seed Photography—Taxi/Getty Images; 108: (left) Czarek
Sokolowski/AP, (right) Dave G. Houser/Corbis; 110: Robert Peary—
Hulton Archive/Getty Images; 111: Roger Mear—Stone/Getty Images;
112: (left) Bill Cooke/AP, (right) Sergio Dionisio/AP; 113: © Steve
Raymer/Corbis; 114: Charlie Neibergall/AP; 115: (top and bottom,
inset) Library of Congress,Washington D.C.; 116: Encyclop.dia
Britannica, Inc.; 117: (top) Encyclop.dia Britannica, Inc., (bottom)
age fotostock/SuperStock; 118: Chinch Gryniewica—Ecoscene/Corbis;
120: Edward S. Curtis Collection/Library of Congress,Washington,
D.C. (neg. no. LC-USZ62-116525); 121: Mimmo Jodice/Corbis;
122: (left and right) The Granger Collection, New York;
123: Bettmann/Corbis; 125: Bettmann/Corbis; 126: (left) © Richard
Hamilton Smith/Corbis, (right) Grant Heilman Photography;
127: Robert Cianflone—Reportage/Getty Images; 128: Tony
Heald/Nature Picture Library; 129: Florian Graner/Nature Picture
Library; 130: (left) Ariana Cubillos/AP, (right) Peter Adams—The
Image Bank/Getty Images; 131: Geogphotos/Alamy; 132: Altrendo
Images/Getty Images; 133: © Spectrum Colour Library/Heritage-
Images; 134: M. Howard/ZEFA; 135: Judie Anderson/EB Inc.;
136: (left) David R. Frazier/Photo Researchers, Inc., (right) Lawrence
Migdale/Photo Researchers, Inc.; 137: Chase Studio/Photo Researchers,