C. H. TYLER TOWNSEND-BIO-GEOGRAPHY OF TEXAS. 
73 
Davis and wine-sap apples, the peach, apricot, quince, sweet potato, to¬ 
bacco, and the hardier grapes, such as the Concord, Catawba, and Isa¬ 
bella, reach their best condition. 
“ (6) Lower Austral Zone , where the long-leaved pine, magnolia, and 
live oak are common on the uplands and the bald cypress and cane in 
the swamps. Here the mockingbird, painted bunting, red-cockaded 
woodpecker, and the chuck-wills-widow are characteristic birds, and the 
cotton rats, rice field rats, wood rats, little spotted skunks, and freetailed 
bats abound. This is the zone of the cotton plant, sugar cane, rice, pe¬ 
can, and peanut; of the oriental pears (LeConte and Kieffer), the seup- 
pernong grape and of the citrus fruits—the orange, lemon, lime, and 
shaddock. In its western portion (the Lower Sonoran) the raisin grape, 
olive, and almond are among the most important agricultural products, 
and the fig ripens several crops each year. 
“ Still further south is the Tropical region, which, in the United States, 
is restricted to southern Florida and extreme southeast Texas, along the 
lower Rio Grande and Gulf coast. Among the tropical trees that grow 
in southern Florida are the royal palm, Jamaica dogwood, machineel, 
mahogany, and mangrove; and among the birds may be mentioned the 
white-crowned pigeon, Zanaida dove, quail doves, Bahama vireo, Ba¬ 
hama honey-creeper, and caracara eagle. The banana, cocoanut, date 
palm, pineapple, mango, and cherimoyer thrive in this belt.” 
It should be stated that Dr. Merriam has since added to the Tropical 
a third district in the U. S., the lower Colorado river valley (Nat. Geog. 
Mag., 1894). 
It will be understood that, from the part of the country treated in this 
paper, we have to do with in the main, with the exception of the Boreal 
and Tropical regions, only the arid portions of North America. By arid 
is meant those portions west of the 97th to the 100th meridian, where 
rains are rare, infrequent, or irregular; in other words, where normal 
humidity ceases and rains can not be depended upon for agricultural pur¬ 
poses, thus necessitating the employment of irrigation for the raising of 
crops. 
Referring again to Dr. Merriam’s zones, as quoted with descriptive de¬ 
tails above, I would substitute the following defining elements in the 
economic and native flora. It must be borne in mind that Dr. Merriam’s 
data refer particularly to Eastern or humid North America, while the 
following refer particularly to Western (or mostly arid) North America; 
but there should be no differences between the east and the west in ordi¬ 
nary crops and fruits, sensible temperatures being equal, except with 
those naturally adapted to an arid region, and all those mentioned above 
by Dr. Merriam for the humid region do equally well and often betfe»* 
in the arid region under irrigation. 
