2*^ ^^ 



^.^y^^O^ • MONTERREY 



'^<i^y^\^ •CIUDAD'^ 

 TROPIC-^OF^CANCER 



T/jf5 15 a small but very distinct and important province. It lies 

 on the west coast of the Gulf of Mexico between the mouth of the 

 San Antonio River in Texas and the region of the port of 

 Tampico in the state of Tamaulipas in Mexico. It forms an 

 almost perfect triangle pointing west: 250 miles along its 

 northern face, 500 miles along its southwestern, and just 400 

 along its eastern, on the coast. Down the middle of this lowland 

 plain flows the Rio Grande River. It is bounded on the north 



by the escarpment leading up to the Edwards Plateau, and on the 

 south by a string of low and ancient mountain ranges that 

 stand isolated on the plain and stretch from a point somewhat 

 north of Monterrey to near Tampico. The western apex of the 

 triangle is at Eagle Pass on the Rio Grande. 



This province contains within its narrow compass in this area 

 the whole of the "North Scrub Belt, the true Desert Belt, and 

 the whole of the South Scrub Belt, which in other parts of the 

 world may each be over a thousand miles wide and which, 

 combined, may in places cover over two thousand miles. All 

 these belts are much compressed here, the Desert being all but 

 squeezed out of existence, appearing only as isolated bare areas 

 and, south of the Rio Grande in its lower reaches, being 

 discernible only by an expert. The scrub belts are profusely 

 vegetated with chaparrals of various kinds. These diminish in 

 luxuriance as one goes west and gradually deteriorate into 

 typical scrub growth at the western apex of the province. 

 Actually, as shown on the map, the desert continues northwest- 

 ward to the Big Bend of the Rio Grande and beyond that onto 

 the Chihuahua Desert, up the Tularosa Valley, and north along 

 the eastern face of the Sacramento Mountains, finally 

 disappearing under the uplands of the South Montane Province. 



South of the string of Ancient Mountains lies a low gutter 

 some fifty miles in width which levels off to a flat, elevated plain 

 to the southwest. This terminates abruptly at the feet of the 

 enormously steep Sierra Occidental, which rises from its edge 

 without so much as a foothill for miles. In fact, for a stretch 

 of some two hundred miles west of Ciudad Victoria, this plain 

 dips down into another slight gutter at their feet. This strip of 

 territory, although supporting a flora looking much like that of 

 the province here under discussion, is not of it, but lies in the 

 great Savannah Belt of the tropics dealt with in Chapter 21. The 

 territory between Eagle Pass and Big Bend is included in 

 Chapter 15. along with the South Montane Province. 



This province, known to phytogeographers as the East 

 Chaparrals, may be divided into first a north and south part by 

 the Rio Grande, and, secondarily, into a series of subbelts cutting 

 across these and parallel to the coast. These are, counting 

 inland from the Gulf of Mexico, a continuous offshore sand strip 

 with dunes, an inland waterway filled with low islands, a 

 swath of almost continuous marshes separated from the real 

 coast by vegetated dunes, a low coastal plain cut by rivers and 

 arroyos, and two wide platforms of slightly increasing altitude. 

 The Rio Grande cuts through all these in a narrow flood plain. 



"arroyos," though the term is inaccurately applied to them, since 

 most have a running stream in their bottoms all year round and 

 some contain considerable rivers that are positively leaping with 

 fish. In fact, I have never entered any river that was more 

 piscinely alive than one that passes through this area. Its 

 shimmering surface meandered between modest clay banks, it 

 was brackish, and it was continuously plopping all over at about 

 ten-foot intervals with leaping fish. When I entered its limpid 

 waters, the hair on my legs and arms was attacked voraciously 

 but weakly by countless catfish and other water creatures. These 

 guUeys or "arroyos" are filled with vegetable growths ranging 

 from lush herbs to towering examples of the upland bushes 

 called "knockaway" or anacua trees (Eritia anacua), cedar-leafed 

 elm, and vast ropes of wild grape (Vitis candicans). There are 

 also veritable hawsers of poison ivy. All of this makes an almost 



jungly mass that fills the gulley to its brim and attracts a large 

 assemblage of birds. 



The best place to see this country at its most typical is the 

 Welder Wildlife Foundation Refuge, a privately initiated insti- 

 tution that lies just at the junction of the coastal and the Rio 

 Grande plains in San Patricio County, Texas. This is composed 

 of slightly rolling country of open grass with scattered stunted 

 cactus, and many grouped bushes of all manner of forms but 

 almost all bearing sharp spines — mesquite, huisache, gum elastic, 

 western hackberry, Mexican persimmon, brezil, and so forth. In 

 the slight depressions of this land are many shallow lakes fringed 

 with rushes and reeds and rank grasses, and upon them innu- 

 merable water birds float gently. On the drier upper areas there 

 is that most enchanting of all native birds, the Road Runner, an 

 impertinent kind of ground-living cuckoo. 



