Records of precipitation at stations in the Papago country-Continued NOTE.-Records from June, 1917, to September, 1918, obtained at Las Moras, 1 mile to the southwest and in about the same relation to the Baboquivari Mountains and Altar Valley. NOTE.-Records from June. 1889. to April, 1899, obtained at Calabasas (altitude 3,440 feet), about 10 miles northwest of Nogales, Records of precipitation at stations in the Papago country-Continued NOTE.-Records from May, 1867, to October, 1875; from May, 1883, to December, 1883; and for September, 1886, obtained at Camp Lowell (altitude 2,530 feet), 7 miles east of Tucson. Records from January, 1916, to December, 1921, obtained at University of Arizona. FLORA THE ARBOREAL DESERT The vegetation of southern Arizona has striking characteristics, which impress even the casual traveler and lend to the region one of its most fascinating charms. This region is one of the most thinly settled parts of the United States, and only a small proportion of the white population subsist on products of the soil, yet in this true |