Moreover,

afford sufficient shade, it has been on the whole a failure. the atmosphere within being slightly more humid and warmer, conduces to fungus diseases among the seedlings. Previous to this several small palm leaf sheds were used successfully.

PLANT COLLECTIONS.

The following collections of economic plants have been assembled:

BANANA PLAT.

About 3 acres of wind-sheltered hillside having a western exposure were set aside for the collection of bananas and plantains. This plat is intended for a variety test, a source for stock distribution of the more valuable kinds, and as an experiment in methods of planting, cultivation, and fertilizing (Pl. XVIII, fig. 2). In regard to the methods of planting, it has been found that the "ñame" (short portion of stem base with corm-like rootstock) was preferable for planting in dry soil; that the "tallo" (3-foot section of stem with root) gave best results in wet soil, and that the "pichón" (2-3-foot sucker or offshoot from stem base) was the most convenient for general purposes. The number of offshoots produced by each of these methods was nearly the same after eight months. Contrary to the popular belief it was indicated that drying the roots in the sun for several days previous to planting was injurious to the vitality of the plant and considerably retarded its sprouting. It is possible, however, that sun-baking may be more or less effective in preventing decay of the root when planted in wet soil. Very few of the "pichones" failed to start into growth within one month after setting, but about 5 per cent of the roots planted by the other methods rotted. Liberal quantities of wood ashes, phosphate rock, nitrate of soda, rotted coffee pulp, and stable manure were used without apparent effect. The plants which have made the best growth thus far are those growing in a heavy red clay which apparently contains very little humus though much moisture.

An experiment to determine the effect of allowing few and many offshoots from the parent plant to remain is in progress; three years will be required to terminate this experiment.

Although but five varieties of this most important fruit are commonly offered for sale in the markets of the island, an unexpectedly large number of the following native varieties has been procured from various parts of the island:

The following varieties were received from the Jamaica Botanic Gardens in January. It is probable that there are four to six reduplications of the native varieties under these names:

The collection of Yautia (Xanthosoma spp.) which was begun in Rio Piedras has been more than doubled, and it is believed to now contain practically all the known varieties. (Pl. XIX, fig. 4). This most valuable root crop appears to be confined to Tropical America, though perhaps the oldest cultivated plant in the world. Experiments have been begun in methods of planting. With one "short season" variety nine kinds of fertilizers have been used; the plant does not readily respond to chemical fertlizers, but stable manure has given very good results.

The collections consists at present of the following 25 varieties:

The question of synonymy can not be fully worked out until the roots are harvested, but judging from the leaf and petiole characters, there is not a great amount of duplication among these names.

Though even the natives of Porto Rico commonly believe that the Yautia never flowers, a photograph of the flower of the "Martinica" variety was taken at the coffee substation (Pl. XX, fig. 3), and evidence was obtained that at least three other kinds have been seen in bloom.

The average market price (1 to 2 cents per pound) of Yautia is about twice that of Taro, or "Malanga."

The very rare and interesting plant which is popularly known as "Yautia del Monte," and which had been considered an Amorphophallus, has been found to be Dracontium asperum, an Aroid from South America, not known to be native elsewhere in the West Indies. Two colonies of the plant occur at the station grounds, and specimens 8 feet high have been measured, the flower photographed, and the seed collected. The corm, sometimes 1 foot in diameter, is dug and eaten

in times of scarcity of other roots; when boiled, it resembles a squash in color and flavor and seems to be free from rhaphides.

YAMS.

The following varieties have been assembled:

From Jamaica Department of Agriculture:

Barbados Table, Lucia.

Yampie, or Indian, St. Vincent.

Negro.

Collected in Grenada, British West Indies:

White Lisbon, St. Kitts.

White, or Water, St. Lucia.

From Hawaii Experiment Station:

Chi.
Hoi.

Native varieties:

Gunda (Dioscorea bulbifera), Congo.
Mapues Morado (D. trifida), Gulém.
Guinéa, Agua.

Purchased: Chinese (D. divaricata).

Six species are represented in this collection. Most of the varieties, however, belong either to Dioscorea aculeata or D. alata.

An interesting yam bean, believed to be Calopogonium cœruleum, is under investigation. For unknown reasons it is very seldom cultivated, but is said to yield large roots of first-class quality.

An exchange of the yam varieties has been instituted between Hawaii and Porto Rico.

MISCELLANEOUS NATIVE CROPS.

Two varieties of the native papaw (Carica papaya) are being compared with a variety the seeds of which were received through Mr. G. N. Collins from Costa Rica.

A

The plat of "Maraca," or edible canna (Canna edulis), is proving less productive at Mayaguez than at Rio Piedras. The small plat at the latter place yielded roots at the rate of about 15 tons per acre. large Hesperid butterfly (Calpodes ethlius) feeds upon the leaves, and a black fungus, the colonies of which occur in circular patches on the upper side of the leaf, is also injurious.

A plat of the rare root crop known as "Llerén” (Calathea allouya) is making a good growth. Though difficult of cultivation, this peculiar plant is highly prized by the natives of the interior, and is even sold in the streets of some of the large towns, the crisp, nut-like tubers ranking with peanuts in popularity.

The native "Malanga" (Colocasia antiquorum esculenta) is under comparison with the "Dasheen" (Colocasia sp. ?) of Trinidad. Our plant thus far appears superior to the imported one.

S. Doc. 148, 58-2-28