esting aroids. There are few crops that can be grown under a greater variety of conditions of climate and soil than the old yautias of the Arawaks. The numerous varieties fall into about eight distinct types, and new ones are being brought to light in Mexico, Central America and Colombia. In Porto Rico the yield of yautias is two to four times that of potatoes, or from five to ten tons an acre. The taros do not yield so heavily, but can be grown in very wet land. The leaves of both taro and yautia are excellent when used as a spinach, the rich milky juice that fills the entire plant giving a "body" not possessed by most greens. Though ranking on a par with sweetpotatoes as to nutritiousness, the digestive principle contained in taro and tanier renders their roots a perfectly safe diet. A kind of taro, called "dasheen" in Trinidad, can be harvested in about six months after planting; and it is believed that this can be grown successfully at least as far north as the Carolinas.

As soon as the great superiority of cassava starch over wheat starch is more widely known, a steady supply from Porto Rico and Hawaii will be necessary, and much work will be done to introduce hardy varieties from Brazil and Colombia, and in selecting seedlings and in hybridizing. Cassava flour made from the yellow- as well as the orange- and white-rooted varieties should find a ready market.

Yams (species of Dioscorea) cannot compete with potatoes in price, and therefore must be studied from the table luxury point of view. Already one kind, the yampee (Dioscorea trifida), has been highly praised in several of the eastern cities, the mealiness, violet color and rich, nutty flavor placing it in the highest class of vegetable foods. The famous East Indian sorts should be introduced into Hawaii and Porto Rico.

The apio (Arracacia esculenta) of Venezuela, as indispensable to Venezuelans as is the potato to Americans, has been recently introduced into Porto Rico, where it already compares very favor

Fig. 116. The date type of dessert banana. ably in price with the native vegetables; and there are indications that it could be grown in southern Florida. It is one of the Umbelliferæ.

Although commonly classed as fruits, the bananas are quite as properly vegetables. Of the fifty or more varieties of bananas, only three are known to

us, the plantain, now a staple article of food in New Orleans, the common Jamaica, and the semiornamental red banana which is occasionally seen in our eastern markets. As soon as a constant and reliable demand is created for plantain flour, banana-coffee and preserves, as well as for the dainty date bananas for desserts (Fig. 116), the planter will no longer grow only the old kind, which ships. well and stays longest in the stomach. Thechayote(Sechium edule, family Cucurbitacea), although in common use by the creoles of New Orleans, has, until recently, remained entirely unknown in the North (Fig. 117). To create a demand for this vegetable, plantings were made in Porto Rico and the Carolinas of the superior Mexican varieties, and the fruits were sent to the chefs of the Waldorf-Astoria and Bellevue-Stratford hotels, who reported most favorably on them, and kept them on their menus as long as the shipment lasted. The fruit is about six inches long.

Tropical nuts.

Fig. 117. Chayote (Sechium edule).

The American taste for salted and roasted nutkernels has grown remarkably in recent years, and the almond orchards of southern Spain have grown accordingly. Yet with this development of a great market for roasted nuts, the planters of the tropics have not awakened to the opportunity nor brought forward one of the most delicate nuts of all, the cashew, Anacardium occidentale, a native of the western tropics. Occasionally seen in confectioners' windows, its name is yet unknown to the public, though in delicacy and sweet flavor no nut in the world can surpass a freshly roasted cashew nut. The London market has in this respect outstripped ours, and on Picadilly the cashew-nut is sold as an expensive delicacy in glass-stoppered bottles. Nor are the posssibilities of the cashew confined to its nuts, for the fruit is delicate, and, either fresh or preserved, is eaten with a keen relish by Americans. Also, a good wine is made from its very juicy pulp. The varieties of this nut-bearing tree have not received even the passing attention of horticulturists, and their number is unknown.

Of all the stately avenue trees of the tropics, none surpasses the Amboina almond (Canarium Amboinense, family Burseraceae), and, although pictured in the reports of the botanic gardens of Java, so far as known the tree has never found its way into the western tropics. The nuts of this tree are sold and relished by Dutch and Javanese alike in the Malay Archipelago, and the kernels have even been recently used with remarkable success by a Dutch pharmacologist as an ingredient of

infant food. Many of the Dutch babies in Java are said to be brought up on it.

Coconuts are known throughout the tropics, yet little has been written on them and no monograph exists on the varieties of this, the most remarkable money-making nut in the world. In the Orient it is estimated that there are twenty to one hundred varieties, and in a single Ceylon collection, which one of the writers has visited, more than a dozen distinct kinds exist, with varying characteristics of tree as well as of nut. Among them is one sort even the husk of which is edible, and another with fruits not over six feet from the ground. Plant introduction should be at work collecting the best of these for trial in the western tropics, determining which are best suited for desiccation and which for copra, for oil, and for butter.

It is of interest to know that a small plantation of the sugar palm (Arenga saccharifera) of the East Indies has been started in Porto Rico. This palm, which may be tapped for about fifteen consecutive years, produces perhaps the most delicious form of sugar in all the vegetable kingdom. Palm nuts, from which each year the millions of buttons of vegetable ivory are made, are imported in amounts valued at more than $5,000,000, yet no culture of any of the four or more species of these plants has ever been undertaken, and the life-history is a matter of conjecture to most botanists. Is the culture practicable, and where can it be conducted on a big scale?

Fibers.

The demand for tropical fiber-plants supports two great monopolies,--the manila hemp industry of the Philippines, and the sisal hemp industry of Yucatan. Neither of these plants-the one a banana, the other a century plant-has been as yet successfully cultivated on a large scale in any other territory than that in which it is at home. Yet the value of the imports of these two fibers into the United States is in the neighborhood of $11,000,000 and $16,000,000, respectively. Two such valuable cultures can scarcely fail to spread into other tropical territories, and already there have been established in Hawaii and Porto Rico small plantings of the sisal hemp which promise to be successful, while plantings of the species of banana which yields the abaca, or manila hemp, are being made in Borneo and Sumatra. The zapupe (Agave sp.) of the Tampico district of Mexico, has several quali

In the markets of Hong Kong are sold each year hundreds of bushels of a hard-shelled, sweet-kerneled acorn, which deserves to be known by the nut-eating public. This tropical oak (Quercus cornea, Fig. 118) is probably cultivated above Canton on the North river, and would, without doubt, thrive in the American tropics, and be not only a decorative addition to the shade trees, but add another delicate nut to the list of nut-foods. The Queensland nut, or Fiji nut (Macadamia ternifolia) is another of the neglected tropical possibilities which deserves to be studied. It is one of the Proteacea. Still another is the Caryocar nuciferum (Ternstræmiaceae), or butternut, of the Guianas and Brazil, one of the largest and best-flavored nuts in the world.

In the culture of the well-known peanut, which is one of the profitable crops of the tropics, the problem receiving most attention is that of the introduction of new varieties. At the present time the Mauritius variety is being imported into Ceylon in large quantities for trial; a Javanese peanut has been a great success in Cochin China; and the oil-producing varieties of West Africa are being tested in the peanut-growing regions of this country.

ties that are superior to sisal hemp, and its culture is also likely to spread.

The rattan of commerce comes from species of climbing palms that are now gathered only in the tropical jungles of the Philippines and adjacent regions. The enormous quantities of this fiber used for chair-bottoms, has in recent years advanced the price materially, and the time of its cultivation may not be far off.

The boll-weevil in the American cotton-belt and the consequent advance in the price of cotton, have set tropical agriculturists seriously to work to find new cotton-growing areas as well as new "resistant" varieties, and the recent introduction of the sea-island cotton into the West Indies, the extension into the Soudan of the Egyptian cotton area, the propaganda for a culture in Ceylon, and the increasing interest in cotton-growing in East Africa and Australia, are evidences of how quickly tropical agriculture is affected by changes in the American and European markets.

Beverage-yielding crops.

Three of the greatest beverages known are the product of tropical plants, yet the merits of those other tropical beverages, the South American maté

(llex Paraguensis) and Arabian kât (Catha edulis, family Celastraceae), have never been given the attention by Americans that they deserve. Of the former, there are some twenty million devotees

Fig. 119. White-seeded cacao.

in South America who consume over fifty-five thousand tons a year; and the natives of Arabia prize the latter so highly that special taxes are levied on the dried leaves and the greatest care is exercised to prevent an evasion of the tax by the grower. Of the innumerable fruit-wines and beerlike "chichas," there are very many in the torrid zone which may some day support small industries.

Tea, originally a plant-culture of the temperate, or at most subtropical zone, in comparatively recent times has become one of the great crops of high altitudes in the tropics, and the history of its introduction into Java, Ceylon and Assam, following the destruction of the coffee estates by the coffee leaf-disease, is one of the interesting chapters in plant introduction. So recently has tea been grown in Ceylon that until three years ago the process of green-tea-making had not been introduced, and in consequence the teas from these regions were all of the black type. Fortune's search through the tea-growing sections of China for the best tea varieties for the British is among the best known expeditions in search of plants for a new agricultural industry.

In coffee-culture, which has undergone so many radical changes since its introduction into the vast plain region of southern Brazil, the future outlook is along the lines of plant introduction. The interest in the new Coffea stenophylla and C. robusta, and the attempt being made by the United States Department of Agriculture to secure for coffeebreeders the original wild coffee of Abyssinia, all show the tendency to recognize the degeneration that has been going on in the cultivated coffeeplant and the need of an invigoration by crosses with the wild type.

The rapid growth of the use all over the world of the cocoa bean and its derivatives, cocoa, chocolate and cocoa butter, has led to the extension in the eastern and western tropics of the areas

devoted to its cultivation, and to a more careful study of the numerous widely different varieties which are in existence. Of all the Central American cacaos only two, the famous and probably the best kinds, Theobroma pentagona and T. bicolor, have been successfully introduced into the great

cacao center of the western hemisphere,Trinidad. Already, Hawaiian planters are calling for the best sorts for their young plantations, and the government is making collections from the West Indies for them as fast as the unusual difficulties of their transportation can be overcome. The white-seeded variety of Porto Rico (Fig. 119), there considered superior to the purple, should be studied; moreover, the quasi-natural hybridization of the six or eight common forms of cacao promises to be a fertile field for the plant-breeder, and there are millions of dollars to be gained by economic methods in the fermentation of the beans.

The kola nut is firmly established in popular knowledge through the beverage called coca-kola. It is derived from uncultivated plants in western Africa, some of which have lately been introduced into the West Indies. According to Cook and Collins, however, the species introduced is not one of the finer varieties from the hinterland, but is the inferior "baboon kola" of the coast region of Liberia.

Grain crops.

The great grain crop of the world is rice,-notwheat or corn, as the American farmer thinks,for there are more people dependent on rice than on any other food in the world. Notwithstanding all the study that has been given its culture, the best rices of one

region are totally unknown to the rice-growers of another, no comparative study of the varieties grown in different countries having been made to find out which are best. Ceylon is following the example set by America and is introducing the Kiushu rice of Japan and the Carolina Gold seed-rice. The American tropics grow mainly upland rices, and these in such small quantities that the tropics depend largely on imports from the Texas and Louisiana rice region for its supply. Porto Rico alone imports over two million dollars' worth of

Fig. 120. Native Mexican method of tapping for rubber.

rice annually, though it contains thousands of acres of irrigable land now idle that should produce more rice than the population of the island con

sumes.

The tropics lie outside the best corn-growing region, and the finest varieties of maize quickly deteriorate when tried in them; but scattered through the torrid zone are many sorts of corn adapted to tropical conditions, which are worthy of introduction and selection.

Plant extracts.

The number of tropical plant species that yield valuable extracts is too long to be more than mentioned. Two examples will show the chaotic condition of their present culture.

Recent discoveries by Professor P. H. Rolfs have shown that in vanilla-culture alone there is a great future for plant introduction. A wild vanilla, carrying a high percentage of vanillin, has been found by him in the Florida swamps, and a trip made by him to the famous Mexican vanilla region revealed that these plantations are producing less than five per cent of their possible output. This state of affairs should encourage the procuring, testing and breeding of the most promising among the thirty or more species of this genus which are scattered over tropical Africa, America and the East Indies.

Only two rubber-producing plants may be said to be actually under cultivation at the present time. The several forms or species of Castilloa (Urticacece) of Mexico and Central America are giving good promise of financial success; and the plantations of Para rubber (Hevea) in the Orient have already yielded profitable returns. Those varieties capable of withstanding a dry climate can probably be grown in Hawaii and the West Indies. Attention should be directed to those plants which, like

Porto Rico is the easternmost island of the Greater Antilles, and is situated between 65° and 671° west longitude, and between 18° and 1810 north latitude. It is a continuation of the range of mountains of which Cuba, Hayti and San Domingo form a part. It is well within the tropics, some 1,400 miles southeast of New York and a little more than that east of New Orleans. The island is thickly settled with a mixed population.

The physical features.

Porto Rico is a parallelogram, extending east and west, approximately 36 miles wide by 100 miles long, embracing an area of 3,600 square miles. The island may be classed as mountainous, the greater part of it being rough and broken. The island is an uplift, the rocks consisting principally of limestone, together with small amounts of granite, marble, sandstone and serpentine. The limestone varies, in some parts being

of a blue or grayish crystalline material, and in others of white and chalky appearance and spongelike in texture. The latter is generally known as coral limestone. Some of these limestones make excellent road-building materials, and also produce a good quality of lime.

The island is bordered by low land of greater or less extent, forming about one-tenth of the whole area. The main range of mountains extends almost due east and west, but the watershed of the northern part of the island is about two-thirds of the entire width; the rainfall on the northern side is also much greater, and the rivers are much larger on that side of the island. The weathering and washing of the mountains has filled up many of the valleys with alluvial soil. These form plains near the seashore, broken here and there by projecting hills.

The interior is cut by deep and narrow valleys, the bottom-lands being small, irregular areas,

occurring first on one side and then on the other of the stream as it sweeps rapidly toward the sea. In some sections of the interior the valleys widen into considerable areas of bottom-land.

The mountains are rough and rugged, but do not extend much over 3,000 feet in elevation. The highest point, El Yunque, is in the northeastern part of the island, which has been set aside by the United States government as a forest reservation. About 75 miles to the north of Porto Rico is one of the deepest parts of the Atlantic ocean,4,600 fathoms, or more than five miles.

The climate of Porto Rico is very uniform in temperature. The rain in most sections is abundant. A part of the day is sunshiny, the humidity relatively high and winds slow and constant. The mean annual temperature is about 78°, the winter months averaging about 8° Fahr. cooler than the summer months. The changes are so slight that they are seldom noticed, the rainfall making the perceptible difference. The mean temperature is slightly lower in the elevated parts of the island, but the weather may be described as perpetual summer. The annual rainfall varies greatly in

The mountains of the island are not high enough to materially modify the temperature, but they have a marked effect on rainfall. The various climatic conditions have a marked influence on vegetation, which is very different in various sections. The soil varies very much in composition. Near the seacoast it consists largely of a coral sand. The flora of this sand is somewhat limited, consisting of coconut palms, yaray palms and sea grapes. Next are the mangrove swamps, which are inundated by rising tides. This soil is made up of a mixture of coral sand and organic matter, the latter giving to it a black color. It is necessarily alkaline, and its usefulness is very limited, except with a great deal of labor and diking.

The playa plains, extending around the island, are alluvial in their origin and vary in different sections. On the northern side they consist of sandy loam underlaid with clay. When they are properly drained they make excellent cane and pasture lands. On the southern side of the island the soil is deeper and usually more sandy. For the production of cane it requires irrigation during the dry season. Bordering the playa plains, the foot-hills soils are usually dark in color. Farther inland the soil is composed of a moist, heavy red clay.

different parts of the island, ranging from 140 to 150 inches as a maximum, to a minimum of about forty inches. As a rule, the winter months are drier, but the seasons vary in duration in different parts of the island. Very heavy rains are sometimes recorded, amounting to as much as ten or more inches in twenty-four hours. The prevailing wind is from the northeast, and in passing over the mountains it is cooled to such an extent that its heavy charge of moisture is condensed and falls on the northern side of the island; for this reason the rainfall on that slope far exceeds that on the other. As a rule, the mornings are cloudless and the showers fall in the afternoon. These showers are often very heavy, but soon pass away. The streams rise very rapidly, and carry much sediment.

Fogs occur in the mountains, but are not common in the lowlands. The climate is generally healthful. There is usually a breeze, and, although the temperature is that of summer, it is not so oppressive as the hot months in the States. The nights are cool and conducive to sleep. Economic features.

There is a railroad extending from San Juan around the western end of the island to Ponce on