In Peru the rubber district embraces the departments of Loreto and San Martin and parts of Junin, Huanaco and Cuzco, including the valleys of the rivers Huallaga, Maranon, Ucayali and Putumayo. This region yields some of the finest Para and a much larger quantity of the best caucho. In this country there is a dependable supply of laborers — na tive Indians — to be had at no other locality in the Amazonian basin.
Bolivia's rubber-yielding territory covers the northern part of that country, including the valleys of the Rio Beni, Rio Mamore, Rio Madre de Dios and other headwater affluents of the Rio Madeira.
The eastern part of Ecuador lies in the most favored section of the Amazonian basin and produces both fine Para and caucho. On the Pacific coast near Guayaquil some plantations have been started.
In Venezuela the rubber country lies along the southern border and along the basin of the Orinoco. The available sources are Hevea Benthamiana and Hevea Cruyanensis. Large plantations have been made in Trinidad and Tobago, but with indifferent results. Other varieties will be tried.
In Panama rubber-gathering is one of the native occupationi. The source is a variety of Castilloa. In 1915 the exports amounted to 70,604 pounds, valued at $18,874.
In Central America various species of Cas tilloa flourish on both sides of the mountain chain, and small plantations have been estab lished in most of the countries. For • some years the collecting of wild rubber was the chief industry of eastern Nicaragua, but the increasing supply of East Indian plantation rubber in the market has so lowered the price that the pursuit has become unprofitable. The same conditions exist in Honduras, the dealers being unable to pay living wages to the laborers. As a consequence, rubber-gathering has nearly ceased.
In British Honduras the rubber industry is carried on along the banks of the Mullins River and in the valleys of its tributaries, along the Sittee River and the Rio Grande in the south and the Sibun River and the upper Belize River in the west. There are also several plantations in the country.
In Mexico, south of the parallel of 22° north latitude, there are no less than nine species of rubber-yielding Castilloas, C. Act being the most productive. Some of these Castilloas flourish on the Pacific coast, some in the semi-arid regions and others on the humid Atlantic coast lands. The rubber area includes the states of Vera Cruz, Oaxaca, Chiapas, Tabasco and Campeche and the terri tory of Tepic. In recent years large plantations
of Castilloas have been set out in the Soconusco and Palenque districts in the state of Chiapas. The aguayulen rubber country lies in the northern part of Mexico in what is known as the Chihuahua Desert on the great central plateau. It covers an area of about 125,000 square miles, though actually occupying only about one-tenth of the acreage. In gen eral its habitat may be delimited as the Texas boundary on the north, the northern boundary of the Mexican state of Durango on the south, the meridian of Santa Barbara, Chihuahua on the west and the meridian of San Luis Potosi on the east. The plant grows most freely along the lower portions of the slopes and on low ridges, but not on the alluvial bottom lands. As to elevation, it is found on levels from 2,000 feet to 10,000 feet atove the sea, but is most plentiful at 6,000 to 6,500 feet, and where the rainfall is from 7 to 10 inches annually. The average stand is about one plant to each square yard. The full-grown plant is 30 to 36 inches high and 40 inches in diameter and weighs from 8 to 10 pounds. The yield of rubber is from 7 to 8 per cent of the weight of the plant. It is estimated that the guayule growth amounts to 500,000 tons, with the total possible yield of 35,000 to 40,000 tons of rubber. The annual output is about 5,000 tons. Formerly, and in some sections to-day, the guayule plants were torn up bodily with the roots, This had the effect of extirpating the plant in those locali ties. The conservative practice is to cut the plant above the root-stock which sends up new branches, and is ready to be cut again in three or four years. The guayule rubber is of supe rior quality when a part of its large content (30 per cent) of resin is removed.
The rubber industry of Latin America has had to meet the momentous industrial fact of the rapid increase in recent years of cultivated rubber raised on plantations where labor is plentiful and cheap. This supply has doubled the market offerings since 1908, during which the cost of collecting wild rubber has been continually increasing. To meet the new con ditions which still larger yields of plantation rubber will bring into •the market situation a reorganization of the labor system and a great improvement in transportation facilities seem imperative, if the wild-rubber industry is to continue prosperous.