Iquitos lies at the head of Amazon River navigation, more than 2,300 miles from the Atlantic seacoast.

protection of our screened-in bungalow. On the way we met a party of five Indians, just arrived by canoe from one of the upper rivers, to meet and conduct back to their settlement an American missionary who was working among them. They wore a garment of hand-woven wool like an inverted bag with an opening for the head. Their thick, black, straight hair was cut in bangs across the forehead. Wild creatures they looked, unlike so many of the Indians met along the river ways and mountain roads.

One of the officers kindly put his cot, the only one in the bungalow, at Mrs. Ker's disposal for the night, and slept on the floor with the rest of us.

The next morning bright and early we were up and ready, greatly pleased that we were to have the chief of the East Peruvian air service as pilot on the last lap of our journey. The day before we had been out to the hangar to inspect our new plane, again a 2-passenger machine, but this time a hydroplane, for now our route was to follow the general course of the river.

At 8.30 we were off, heading down river for Iquitos, only three or four hundred miles distant. We were not always within gliding distance of the river, and though the monotonous green of the jungle,

2,000 feet below us, looked soft and safe, we realized its deceptive appearance and the probable hopelessness of ever getting out of it alive if forced to seek a landing in the branches of its mighty trees. Against all that background of green and water, hovering spots of white-innumerable herons-were the only signs of life, although we knew the jungle to be teeming with parrots and other birds of the most brilliant plumage, boa constrictors and anacondas, deer and jaguars, tapirs and crocodiles, monkeys of countless varieties, beautiful butterflies, and a thousand different forms of life.

An hour after leaving Masisea we dropped down for gasoline at Contamana, a river town on the Ucayali gradually being washed away by the floods of that mighty river; we were off once more, the seemingly interminable jungle stretching away in all directions. We reached Requena, circled low, dropped a package of mail in the plaza, and again headed for Iquitos.

We had been gone from Masisea five hours. A hard wind was blowing against us, drops of rain stung us in the face, and we felt the vibration of the struts, and sudden jerks as we dropped in the air pockets. We rose to higher levels and a superb view opened below us the junction of the Ucayali and Marañon rivers, the two great confluents of the Amazon.

An hour more and we saw in the distance on the river bank a glistening spot of white which gradually resolved itself into a city-Iquitos at last. The plane descended in a graceful spiral, and we found ourselves on the bosom of the Amazon. Our journey was over, and Mrs. Ker had the distinction of being the first American woman to make the flight.

The little city of Iquitos, with its 20,000 inhabitants, lies only 328 feet above the level of the Atlantic; an ocean-going steamer was loading at the dock when we arrived, although the ocean is 2,400 miles distant. Surprising, you say? Yes, and another surprise was in store for us, a pleasant one, for never in our travels had we met people of greater charm than those whom we were to know in this little city, hidden in the heart of the jungle, 3 degrees south of the equator.

generally known tapioca, and a starch which is extensively used by laundries of the United States. Indigenous to tropical Latin America, the cassava is one of the world's most widely used economic plants. Its derivatives include meal and flour, in addition to the Products of the plant are also utilized as a livestock feed, and in

the manufacture of glues, pastes, and explosives.

CASSAVA: AN ECONOMIC PLANT
NATIVE TO LATIN AMERICA

By José L. COLOM

Chief, Division of Agricultural Cooperation, Pan American Union

HE cassava is one of the most extensively grown and widely used economic plants known to man. With the exception of corn, beans, and potatoes, it is of all the indigenous plants of America the one whose culture is most widespread throughout the world. It grows well in every tropical country, and is to be found in all lands within the limits of 30° latitude north and south of the Equator where growing conditions are at all favorable. The tuberous, starchy root of this plant forms the chief article of diet for millions of tropical people; in this rôle it ranks perhaps next to rice. While the inhabitants of temperate regions are familiar with only one or two of its manufactured products, such as the tapioca eaten occasionally as a dessert or used in the preparation of other foods, in many parts of South and Central America cassava is eaten by all classes of society twice a day nearly every day in the year. One of the most nutritious foods known, it is propagated very easily and has indeed been growing in a wild state in tropical America since before the Spanish and Portuguese settled in that part of the western world. Yet it is only in comparatively recent years that peoples of the Tropics, particularly in the cassava's native American habitat, began to realize its importance as an economic plant.

NOMENCLATURE

In the United States the name cassava is properly given to the plant Manihot utilissima Pohl., though even here it is known also by various others. Other scientific names applied are Jatropha manihot Linn., and Janipha manihot H. B. K., while in South America the common names by which it is known include manihot, manioc, aypi, and yuca. For obvious reasons it is sometimes referred to as the tapioca plant or the sweetpotato tree, the latter because of a similarity in the root growth of the two plants. When it was introduced into India it was given a dozen or more different vernacular names in the various states, which literally translated mean "bread yam," "stick sweetpotato," "flour tree," and similar descriptive phrases.

BOTANIC DESCRIPTION

The cultivated cassava is a shrubby tree growing 3 to 10 feet in height, with stem and branches forking regularly in threes. It has long

petioled palmately-parted leaves of from 5 to 13 divisions, reaching nearly to the base, elliptical in outline and forming fingers. In appearance the plant resembles the castor-bean (Ricinus communis Linn.), both being genera of the Euphorbiaceae family. The color of the roots varies from dark red to light yellow or almost white, their length from 1 to 6 or 8 feet or more, and their diameter from 1% to 2%1⁄2 inches. There are usually from 3 to 5 storage roots, in which starch is kept as food for the plant; they grow radially from the base of the plant and rather close to the surface of the ground and are the roots of commercial importance.

Two types of cultivated cassava are usually designated, "bitter" and "sweet," the former represented by the species Manihot utilissima Pohl., and the latter by Manihot aipi Plon. The distinction is due to the presence in their roots of the volatile hydrocyanic (prussic) acid compound, the former type containing considerably more than the latter, or as much as 0.03 per cent and more of the root content. In spite of this fact, varieties of the bitter cassava are much more widely used as food in the Tropics, mainly because they produce more abundantly. In both types most of the acid is lost by processing the roots, or driven off by heat in drying the starch or roasting or cooking the

roots.

There are many different varieties now known, though only a few are commercially important. In Java, where perhaps greater strides have been taken in cassava cultivation and exploitation than elsewhere, 25 are considered to be important, while in the Philippines only 2 or 3 are of wide distribution. In 1919, J. Zehntner made a study of 74 different varieties of Brazilian cassava. Many new ones have been developed from time to time, all through propagation by seeds; the commercial system of propagation, which will be discussed later, is by means of cuttings.

CHEMICAL ANALYSIS

In view of the growing interest shown by many countries in the use of cassava flour as a substitute for wheat flour, it may be worthwhile to say something about its composition. The Bureau of Chemistry of the United States Department of Agriculture found that cassava flour could not be substituted in full for wheat flour in making bread, largely because of its excessive carbohydrate content and lack of nitrogenous bodies. For instance, ordinary wheat flour contains nitrogenous compounds varying from 8 to 14 per cent, while in cassava flour they rarely are as much as 2 per cent. For this reason the rôle of cassava flour in bread making must necessarily be confined to that of a partial substitute to be used with wheat flour, at least if present baking methods continue.