MAMMALS OF THE MEXICAN BOUNDAKY. 25 



and severity, the effects of wbich were intensified by the overstocl^ed condition 

 of the ranges. This state of affairs added greatly to the difficulties and expense 

 of the survey. Vegetation was parched, water holes dried up, and scarcely any 

 grass was left by the famishing cattle. This long drought was broken by 

 abundant rains in July and August, 1893, but not until the stock-raising inter- 

 ests had suffered severely. 



The small rainfall of this region generally occurs at two periods of the year — 

 midwinter and midsummer — the latter rainfall the greater and by far the most 

 important ; consequently this period is known as the " rainy season." The 

 summer rains generally commence about the 1st of July and cease sometimes 

 between the Ist and 20th of September. It is soon after the first of these rains 

 that vegetation in this region begins to assume a spring-like character. Leaves 

 burst forth, the hills and valleys are covered with grass, and a bewildering pro- 

 fusion of wild flowers covers the entire country. As if conscious of the short 

 duration of the rainy season these grow with great rapidity, and their seeds 

 mature ere the rains cease. In a month of so thereafter they have assumed 

 the somber colors typical of fall and winter. Thus in the short space of three 

 or four months vegetation here enjoys its spring, its summer, and its autumn. 



Before going more into details it may be well to note certain general charac- 

 teristics of this region which at once strike the ordinary traveler. 



These are the bare, jagged mountains rising out of the plains like " islands 

 from the sea ; " the abundance of the evidences of volcanic action in times geo- 

 logically recent ; the parallelism of the mountain ranges with one another and 

 with the Pacific coast ; the general absence of trees ; the preponderance of ever- 

 green vegetation, and its dull, leaden-green hue; the prevalence of thorns in 

 nearly all vegetation ; the general absence of fragrance in flowers ; the resinous 

 character of the odor of the most common trees and shrubs, and the abundance 

 and large size of the cactus. 



Tift entire country along the boundary is thinly settled, the principal settle- 

 ments within 20 miles of the boundary on either side being at Lake Palomas, 

 Hachita, the Sulphur Spring Valley, La Morita, the San Pedro Valley, the 

 Huachuca Mountains, the Santa Cruz Valley, Oro Blanco, Arivaca, the Baboqui- 

 vari Valley, the Papago rancherias of Pozo Verde, Cobota, and Pozo de Luis, 

 the Sonoyta Valley, the Colorado River Valley, and the country between the 

 summit of the Coast Range and the Pacific. The only towns within the limits 

 above mentioned are Bisbee, Santa Cruz, Nogales, Yuma, and San Diego. With 

 the exception of these towns and settlements the rest of this zone of about 

 24,000 square miles contains less than 100 permanent inhabitants.'^ 



It is rather remarkable that an arbitrarily chosen line like the one under dis- 

 cussion should, between the Rio Grande and Colorado River, follow almost 

 exactly the summit of the divide which separates the waters flowing north into 

 the United States from those flowing south into Mexico. 



Inhabitants. — Many long stretches of the boundary region are 

 almost without inhabitants other than Indians and a few Mexicans. 

 Where there is grazing, the cowboys are found in bands looking after 

 their cattle and herds of horses; but even in such places the stock 

 ranches are scattered far apart. The fleeting " vinaterias " of Mexi- 

 can " mescal " makers are occasional in canyons of the mountains, 

 and mines, or " prospects," were found in similar localities. 



« Although the soil in many places is very fertile, yet the great scarcity of 

 water renders it Impossible for the inhabitants to carry on agriculture except 

 to a very limited extent. 



