Collection. 182 (bc) PCL/Alamy. (bl) Corbis. (mc) Axel Leschinski/Alamy. (ml) Albert Harlingue/Roger Viollet/The Image Works. (mr) Axel Leschinski/Alamy. (tc) Yasushi Akimoto/Getty Images. (tl) BananaStock/Jupiterimages/Alamy. (tr) Brian Drouin/National Geographic Image Collection. 193 (c) Courtesy of Tatsuro Kiuchi. (t) Courtesy of Sherry Garland. 198 (b) Comstock/Corbis. 200 (b) Getty Images. 201 (l) Lawrence Manning/Corbis. (r) M L Pearson/Alamy Images. 202 (b) AP Photo/Roswell Daily Record, Bill Moffitt. 204 (mc) SW Productions/Getty Images. (ml) Directphoto.org/Alamy. (ml) Lewis Hine/National Geographic Image Collection. (tc) Nina Berman/National Geographic Image Collection. (tl) blickwinkel/Alamy. (tr) Nicole Duplaix/National Geographic Image Collection. 206–207 (l) Steve Hamblin/Alamy. 207 (br) Bill Ross/Corbis. 210 (b) Micahel Stravato/Corbis Sygma. (t) Tom Grill/Photographer’s Choice. 211 (t) Alan Schein Photography/Corbis. 212 (b) Owen Franken/Corbis. 213 (b) Angelo Cavalli/SuperStock. (c) Art-Images/Alamy Images. (t) J Marshall/Tribaleye Images/Alamy Images. 214 (b) David Young-Wolff/PhotoEdit. (t) Kokyat Choong/Alamy. 215 (b) David Young-Wolff/PhotoEdit. 216 (b) DreamPictures/Taxi. 217 (r) Tim Boyle/Getty Images. 222 (b) Photo by Joe Raedle/Getty Images. 226 (b) Grant Faint/Getty Images. 227 (l) Image Source—Hola/Alamy Images. (c) Design Pics/Corbis. (r) Peter Titmuss/Alamy Images. 228 (bl) John Lund/Sam Diephuis/Getty Images. (mc) David Madison/Getty Images. (ml) Bob Daemmrich/PhotoEdit. (tc) Todd Gipstein/National Geographic Image Collection. (tl) Ed George/National Geographic Image Collection. (tr) Michael Newman/PhotoEdit. 230–231 (bg) moodboard/Corbis. 233 (bg) moodboard/Corbis. 234 (bg) moodboard/Corbis. 236 (bg) moodboard/Corbis. 238 (bg) moodboard/Corbis. 241 (bg) moodboard/Corbis. 243 (bg) moodboard/Corbis. 245 (bg) moodboard/Corbis. 246 (bg) moodboard/Corbis. 247 (c) Margaret H. McIntyre/Lee & Low Books. 248 (t) Wendy Stone/Corbis. 258 (c) Robert Daly/Stone/Getty Images 261 (r) David Epperson/Getty Images. 263 (t) Jupiter Images. (b) Roy Morsch/age fotostock. 264 (bg) Micro Discovery/Corbis. (bl) Herbert Spichtinger/zefa/Corbis. 265 (c) Blend Images/Alamy Images. 266 (b) Superstudio/Getty Images. 268 (bc) Jozsef Szentpeteri/National Geographic Image Collection. (bl) Sarah Leen/National Geographic Image Collection. (mc) Phototake, Inc/Alamy. (ml) Michael Newman/PhotoEdit. (mr) Blend Images/Alamy. (tc) 3DClinic/Collection Mix: Subjects/Getty Images. (tl) Wim van Egmond/Getty Images. (tr) Michael A. Keller/Corbis. 270–271 (bg) Paul J. Sutton/Duomo/PCN Photography. 272 (l) Al Bello/Getty Images. 273 (bl) Manfred Kage/Peter Arnold, Inc. (br) Comstock/Jupiterimages. 274 (t) Rubberball/Getty Images. 275 (br) Jenny Acheson/Getty Images. (mr) Mike Kemp/Getty Images. (tr) Thinkstock/Corbis. 276 (t) M. Nader/The Image Bank/Getty Images. 277 (br) Randy Faris/Corbis. (mr) Randi Anglin/Syracuse Newspapers/The Image Works. (tr) Caroline Woodham/Getty Images. 278 (bl) David Young-Wolff/PhotoEdit. (tl) William West/AFP/Getty. 279 (b) Richard T. Nowitz/Corbis. 280 (bg) James Isbell/Istockphoto. 282 (b) Michael A. Keller/zefa/Corbis. 286 (bg) MedicalRF.com/Corbis. (bl) Lester Lefkowitz/Corbis. 287 (c) David Ashley/Corbis. 288 (b) Patrik Giardino/Corbis. 290 (bc) Christy Krames. (bl) Sara Zinelli/Alamy. (mc) Envision/Corbis. (ml) Phil Schermeister/National Geographic Image Collection. (mr) Luedke and Sparrow/Digital Vision/Getty Images. (tc) image100/Corbis. (tl) Davis Meltzer/National Geographic Image Collection. (tr) Steven Hunt/Getty Images. 292–293 (bg) Al Francekevich/Getty Images. 296 (c) Pete Saloutos/Corbis. 297 (r) Louie Psihoyos/Science Faction/Getty Images. 299 (r) ABiomed/Getty Images. 300–301 (c) Precision Graphics. 302 (b) Jon Feingersh/zefa/Corbis. 306 (c) Nik Wheeler/Corbis. 308 (b) Jerry Wachter/Sports Imagery/Getty Images. 309 (c) Wally McNamee/Corbis. 310 (b) ullstein—CARO/Riedmiller/Peter Arnold, Inc. 312 (mc) Priit Vesilind/National Geographic Image Collection. (ml) Warren Morgan/Corbis. (mr) Randy Faris/Corbis. (tc) Tanya Constantine/Getty Images. (tl) Barry Austin/Getty Images. (tr) Jose Luis Pelaez Inc/Getty Images. 314–315 (b) Beathan/Corbis. (c) Beathan/Corbis. (t) Design Pics/Corbis. 316 (b) Sean Justice/Corbis. (t) David Lubar. 317 (b) Sean Justice/Corbis. 318 (c) Nikreates/Alamy. 319 (b) SW Productions/Brand X/Corbis. (c) Beathan/Corbis. 321 (c) Bettmann/Corbis. 322 (c) Jupiterimages/Comstock Images/Alamy. 323 (b) Mike Powell/Allsport Concepts. 324 (t) David Lubar. 325 (c) David Lubar. 330 (b) Cleve Bryant/PhotoEdit. 336 (b) Getty Images/Dorling Kindersley. 337 (t) Michael Bishop/Illustration Works/Corbis. 338 (t) AP Photo. 339 (t) Kim Steele/Getty Images. 341 (t) Robert Harding Picture Library Ltd/Alamy Images. (b) De Agostini/Getty Images. 342 (bg) Serge Bogomyako/Alamy Images. (b) Peter Dennis/Dorling Kindersley/DK Images. 343 (c) Franck Robichon/epa/Corbis. 344 (b) Getty Images/PhotoAlto. 346 (bc) Ariel Skelley/Taxi/Getty Images. (bl) pixtal. (mc) Jeff Greenberg/Alamy. (ml) Alaska Stock. (mr) Jon Feingersh/Corbis. (tc) Blend Images/Alamy. (tl) Michael Newman/PhotoEdit. (tr) Joel Sartore/National Geographic Image Collection. 348–349 (bg) Dick Luria/Taxi. 358 (b) Blue Trimarchi/Scholastic Inc. (t) Jason Stemple Photographer. 364 (bg) Peter Horree/Alamy Images. (b) John Neubauer/PhotoEdit. 367 (l) Getty Images. 367 (r) Getty Images/Inti St Clair. 368 (bc) Topham/The Image Works. (bl) James Osmond/Alamy. (mc) PhotoBliss/Alamy. (ml) Hulton-Deutsch Collection/Corbis. (mr) Jodi Cobb/National Geographic Image Collection. (tc) Dennis Flaherty/Photodisc/Getty Images. (tl) Nick White/Getty Images. (tl) Bob Daemmrich/PhotoEdit. 370–371 (bg) Nik Wheeler/Corbis. (t) Rebecca Hale. 372 (t) Rebecca Hale. 373 (t) The Trustees of the British Museum, photo by Victor R. Boswell, Jr. 375 (bl) The Granger Collection, New York. (ml) Pictorial Press Ltd/Alamy. (tr) Diego Duran/The Bridgeman Art Library. 376 (b) John Pohl/Foundation for the Advancement of Mesoamerican Studies, Inc. www.famsi.org. (c) Museum für Völkerkunde Vienna/Dagli Orti/The Art Archive. (t) Illustration by Ned Seidler. 377 (t) Sisse Brimberg/National Geographic Image Collection. 378 (bg) Ann Johansson/Corbis. 379 (b) Tetra Images/Alamy. 380 (b) Corbis Premium RF/Alamy. 383 (t) Martin Harvey/Corbis. 384 (b) Getty Images/Hulton Archive. 386 (b) The Granger Collection, New York. 387 (c) The Granger Collection, New York. 388 (b) Richard Hutchings/PhotoEdit. 390 (bl) Siri Stafford/Digital Vision/Getty Images. (mc) Richard T. Nowitz/Corbis. (ml) Pat Doyle/Corbis. (tc) Scott Sinklier/Corbis. (tl) Myrleen Ferguson Cate/PhotoEdit. (tr) Theo Allofs/Corbis. 392–393 (bg) M. Timothy O’Keefe/Alamy. (fg) Library of Congress, Prints & Photographs Division, John C. H. Grabill Collection, [LC-DIG-ppmsc-. 2508]. 394 (c) North Wind Picture Archives. 400 (c) Terry Eiler. 401 (t) Blue Lantern Studio/Corbis. 402 (b) Library of Congress, Prints & Photographs Division, Edward S. Curtis Collection, [LC-USZ62-48395]. 403 (b) Layne Kennedy/Corbis. 404 (c) Christie’s Images/Corbis. 405 (c) Christie’s Images/Corbis. 406 (r) Blue Lantern Studio/Corbis. 417 (r) Sami Sarkis/Getty Images. 419 (c) Toby Talbot/AP Images. 420 (bg) Philip Nealey/Getty Images. (b) Michael Newman/PhotoEdit. 421 (t) Eric Meola/Getty Images. (b) Paul A. Souders/Corbis. 422 (b) blickwinkel/Alamy Images. 424 (mc) Liz Garza Williams. 424 (ml) Tim McGuire/Corbis. (mr) VCL/Spencer Rowell/Getty Images. (tc) David Young-Wolff/PhotoEdit. (tl) Spencer Grant/PhotoEdit. (tr) Jeff Cadge/Getty Images. 428–429 (bg) Layne Kennedy/Corbis. 430 (bg) Bruce Clarke/Index Stock Imagery. 431 (r) AP Images. 433 (b) Richard Olsenius/National Geographic Image Collection. (t) Owen Franken/Corbis. 434 (b) Gambarini/dpa/Corbis. 434 (t) Aurora/Getty Images. 435 (t) Photo courtesy of Guide Dogs for the Blind, www.guidedogs.com. 436 (bg) Larry Lee Photography/Corbis. (r) Underwood & Underwood/Corbis. 440 (bg) Matthias Kulka/Zefa/Corbis. (b) Robert W. Ginn/PhotoEdit. 441 (l) Scott Lituchy/Star Ledger/Corbis. (r) Goodshoot/Corbis. 444 (bc) Hans Neleman/Getty Images. (bl) Richard Olsenius/National Geographic Image Collection. (mc) Stephen St. John/National Geographic Image Collection. (ml) Mike Hewitt/Getty Images. (mr) Richard Nowitz/National Geographic Image Collection. (tc) Daniel Bosler/Photographer’s Choice/Getty Images. (tl) INSADCO Photography/Alamy. (tr) Rudi Von Briel/PhotoEdit. 446–447 (bg) Marc Lester/Anchorage Daily News/AP Images. 448 (bg) Jurgen Vogt/Iconica. (tc) Marc Lester/Anchorage Daily News/AP Images. (tl) Richard Hutchings/PhotoEdit. (tr) David LeMaster/Aniak Volunteer Fire Dept. 449 (bg) Jurgen Vogt/Iconica. (ml) David LeMaster/Aniak Volunteer Fire Dept. (tl) Richard Hutchings/PhotoEdit. (tr) David LeMaster/Aniak Volunteer Fire Dept. 450 (bg) Jurgen Vogt/Iconica. (tl) Richard Hutchings/PhotoEdit. (tr) David LeMaster/Aniak Volunteer Fire Dept. 451 (bg) Jurgen Vogt/Iconica. (ml) David LeMaster/Aniak Volunteer Fire Department. (tl) Richard Hutchings/PhotoEdit. (tr) David LeMaster/Aniak Volunteer Fire Dept. 452 (b) Roberta Fields. (bg) Jurgen Vogt/Iconica. (ml) David LeMaster/Aniak Volunteer Fire Dept. (tl) Richard Hutchings/PhotoEdit. (tr) David LeMaster/Aniak Volunteer Fire Dept. 456 (b) Cartoon copyrighted by Mark Parisi, offthemark.com. Printed with permission. 458 (bg) imagebroker/Alamy Images. (b) Getty Images. 459 (c) Catherine Karnow/Corbis. 460 (b) Parque/zefa/Corbis. 462 (bc) Matthieu Spohn /Getty Images. (bl) Alexander Zemlianichenko/AP Images. (mc) Neo Vision/Getty Images. (ml) Brian Drouin/National Geographic Image Collection. (mr) Bettmann/Corbis. (tc) Stockbyte/Getty Images. (tl) Ira Block/National Geographic Image Collection. (tr) David Madison/Getty Images. 471 (b) Lawrence Manning/Corbis. 472 (t) Kathy Willens/AP Images. 473 (bg) Peter Greste/AFP/Getty Images. 475 (b) Peter Greste/AFP/Getty Images. (t) Antony Njuguna/Reuters. 476 (bl) Peter Greste/Reuters/Corbis. (tl)Antony Njuguna/Reuters. (tr) AP Images. 477 (bl) Beverly Joubert/National Geographic. (br) Wolfgang Kaehler/Corbis. (t) Peter Johnson/Corbis. 478 (b) Antony Njuguna/Reuters. 489 (r) Stockbyte/Getty Images. 491 (t) moodboard/Corbis. (b) Mary Langenfeld/Alamy Images. 492 (bg) Paul Kern/Alamy Images. (b) Kelly-Mooney Photography/Corbis. 493 (c) Associated Press/Ted S. Warren. 494 (b) Rudi Von Briel/PhotoEdit. 496 (bc) Chris Clinton/Taxi/Getty Images. (bl) Richard Nowitz/National Geographic Image Collection. (mc) Ira Block/National Geographic Image Collection. (ml) Jeff Greenberg/Alamy. (mr) Corbis. (tc) JupiterImages/Pixland/Alamy. (tl) Bruce Dale/National Geographic Image Collection. (tr) Randy Faris/Corbis. 498–499 (bg) William Manning/