Page:Popular Science Monthly Volume 51.djvu/587

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FRAGMENTS OF SCIENCE.
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ordinary writing material of the oldest times. The earliest example is the Horiazi palm-leaf Sanskrit MS. of the sixth century a.d., which is preserved in Japan, and of which the Bodleian Library, Oxford, possesses a facsimile. In northern India, where they were written on with ink, palm leaves ceased to be used after the introduction of paper; but in the south, where the writing was scratched in with a stylus, they are still employed. Paper was introduced by the Mohammedans, and has been very extensively used for manuscripts. The oldest Gujerat paper manuscript dates from the beginning of the thirteenth century. Neither varnished boards, such as are used in Burma for manuscripts, have been found in India, nor leather or parchment, which the regulations against impurity of materials would forbid Hindus from using. Copper plates were early and frequently used for inscriptions. They furnish a curious illustration of the narrowness of the limits of invention, in that they practically all imitate the shape either of the palm leaves or of strips of birch bark.

Arid Yucatan.—The second contribution by Dr. C. F. Millspaugh to the Field Columbian Museum, on the Coastal and Plain Flora of Yucatan, relates to a region peculiar in its biological character, and differing essentially from the surrounding regions, especially in its flora. There all plants have a desiccated appearance, due to their struggle against drought, while in the neighboring areas—Honduras, Guatemala, Chiapas, and Tabasco—the wealth of exuberant vegetation is marked. The difference is brought about partly by orographic features—the other regions having elements of mountain and ridge and large streams of which the Yucatan region is destitute, and its soil and coralline substratum being so porous that whatever rain falls quickly filters into cavities, caverns, and faults beneath the surface. Hence the only residual supply of water available for vegetation is held in the peculiar sartenejas, aguadas, and cenotes. The sartenejas are depressions in the plain, from a few ounces to several hogsheads in capacity, at the bottom of which sufficient marshy soil has been formed to retain such water as falls into them. These soon dry up after the rainy season and their vegetation lies dormant. The aguadas are simply larger sartenejas, usually of circular outline and from fifty to one hundred feet in diameter. They retain stagnant water and maintain a growth of mud plants throughout the year. The cenotes are deep, perpendicular-walled, nearly circular wells, penetrating the floor of the plain and opening into an abundant supply of clear, cool water, saturated with carbonate of lime. They are from a few feet to a hundred yards or more in diameter, and from thirty to two hundred feet deep to the water level, and prove by their frequency and extent that this great plain is as freely watered far below its surface as most countries are above. Mr. Millspaugh's list of plants collected in this region and its islands includes 418 genera and 734 species.

Owl Trees.—It is common knowledge or common supposition that owls nest in the hollows of trees; and since sentiment is turning to regard these birds as beneficial enemies of vermin rather than noxious destroyers of useful things, talk is occasionally heard of protecting and encouraging them—as Sir Montstuart Grant Duff has done. An English writer has been investigating their nesting places, and finds that they prefer pollard elms in which repeated cuttings have caused growths of gnarls and protuberances and all sorts of shapeless hiding places. In one of these trees become a habitation of birds he found the center of the crown forming a kind of platform walled round by the ruins of what should have been branches. The floor of the platform was constituted of rotten wood, leaf mold, and dead sticks, mixed with the bones and fur of "finely pulverized mice." "The bases of the branches, or what should have been branches, were hollow shells, often measuring yards across, with various holes, bulges, knots, and cracks, some piercing the sides, some making only side chambers and shelves. These caverns are the chosen home of the white owl. In one she sleeps, in another she lays her eggs, in a third she has her larder when the young owls are growing up. In another similar tree, if one be near, her husband sleeps by day; and from any one of the doors or windows she slips out and flies noiselessly across the meadow when an intruder scrambles into