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GRICULTURAL science so generally appears as a borrower from physics, chemistry, botany or zoology that it has not been expected to furnish facts of use in other lines of investigation. Thus, although it has been known since the sixteenth century that the same series of food plants extended throughout the tropics of both hemispheres, the significance of this is still unappreciated, and ethnologists are still doubtful regarding prehistoric communication across the Pacific. Stranded Japanese junks, Buddhist missionaries, Alaskan land connection and other possibilities of contact have been gravely and minutely discussed while unequivocal evidence of extensive early intercourse lay only too obviously at hand.

The history of agriculture shows a conservatism probably unequaled in any phase of human activity. Not only has no important food plant been domesticated in historic times, but even in the most enlightened communities changes in the culture and use of the food plants and products to which our physical constitutions and domestic customs have become adapted take place with extreme slowness except as they accompany movements of colonization. Remembering this strict self-limitation of man to traditional food materials, it becomes obvious that the possession of the same seedless plants, such as the yam, sweet potato, taro, sugar-cane and banana by the primitive peoples of the islands of the Pacific, as well as by those of the adjacent shores of Asia and America, indicates, with attendant facts, not only an older communication, but an intimate contact or community of origin of the agricultural civilizations of the lands adjacent to the Pacific and Indian Oceans.

Notwithstanding the immense distances by which the tropical islands of the Pacific are separated from the continents and from each other, European discoverers found them already occupied by an adventurous sea-faring people who knew enough astronomy to navigate their frail canoes in these vast expanses of ocean without the assistance of the mariner's compass. The agriculture of the Polynesians was, however, no less wonderful than their seamanship, and was certainly not less important to them, since the coral islands of the Pacific are not