National Geographic : 1914 May
RIVER FRONT OF TAMPICO, MEXICO Photo by Frank M. Chapman treatment; a rubber planter went south to the Isthmus, an oil-man north to the petroleum deposits near Tuxpam, and an archeologist left for the ruins on the table-land. Some came to buy, others to sell, and in more settled lands we might have had small interest in them or their calling, but your commercial man in the tropics is often an adventurer at heart and an explorer in practice, and if his reports to his "house" never reach the pages of a geographic magazine, we may admit that they not infrequently contain more novel information than many reports that do. Gratefully do I acknowledge my debt to these Knights of Trade, whose intimate knowledge of little-known trails and places has been of no small value in solv ing problems of transportation and sub sistence. WE PASS THROUGH TROPICAL, TEMPERATE, AND BOREAL ZONES IN 75 MILES My own mission in Mexico was to make field studies and collect specimens and accessories for an American Mu seum Habitat Group, designed to illus trate the effect of altitude on the distri bution of life; and the fact that nowhere on the American hemisphere can this be done so effectively as in the country lying between sea-level and snow-line on Mt. Orizaba, is in direct support of the claims made for the diverse interests of this truly wonderful region. Reference to a map of the natural life areas of North America shows the tropic region stretching up two narrow arms on the Gulf and Pacific coasts of Mexico which, in places on the higher Sierras, are paralleled by southern extensions of the Canadian Zone of the north. Be tween the two lie bands of the Temper ate Zone. Thus, in our journey from the Gulf to the summit of the Sierra, we pass through Tropical, Temperate, and Boreal zones-the Tierras Caliente, Templada, and Fria, of the native. Our actual jour ney, in passing from sea-level to snow line, may be a matter of 75 miles, our change of altitude approximately three miles; but if we were to seek the Cana dian Zone not on mountain top but on the coast, it would be necessary for us to travel to Maine or Nova Scotia. In other words, a journey of some 1,500 miles would be required to reach conditions which are here distant but three altitu dinal miles.