Page:Popular Science Monthly Volume 39.djvu/289

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Function of Cypress Knees.—The cypress tree (Taxodium distichum) of the Southern swamps is marked by a peculiar growth of protuberances rising above the soil in the region of the roots, and called knees. The purpose of the knees has not been satisfactorily determined. They have been regarded by botanists as simply affording a means for securing the aeration of the sap when the roots are too deeply covered with water to permit them to serve that purpose. Mr. Robert H. Lamborn, after examining the trees in the swamps, has come to a different conclusion. He believes that the knees secure a firm hold to the tree in the exceedingly loose soil in which it grows. The formation of knees is accompanied by roots projecting more or less perpendicularly into the earth. The knee, when fully developed, is generally hollow, comparatively soft, gnarled, and hard to rupture, so that it has the quality of a spring that becomes more rigid as it is extended or compressed out of its normal shape. "When, in a hurricane, the great tree rocks back and forth on its base, and with its immense leverage pulls upon this odd-shaped wooden anchor, instead of straightening out in the soft material, as an ordinary root might, thus allowing the tree to lean over and add its weight to the destructive force of the storm, it grips the sand as the bower-anchor would do, and resists every motion. The elasticity at the point of junction allows one after another of the perpendicular flukes attached to the same shank to come into effective action, so that before being drawn from the sand or ruptured the combined flukes present an enormous resistance." The knees, with their sharp tips, may also serve the purpose of catching the drift of plant-food as it floats on the currents of floods, and effecting its deposition. Mr. Lamborn adds, in his articles in Garden and Forest and the American Naturalist, an observation regarding the roots of other trees that trench upon soils affected by the cypress, and often take advantage of the anchors it sets in treacherous bottoms. They project their cable-like, flexible roots in every direction horizontally, interlacing continually until a fabric is woven on the surface of the soft earth like the tangled web of a gigantic basket. Out of this close wickerwork, firmly attached to it, and dependent for their support upon its integrity, rise the tree trunks. Thus slowly, and by a community of growth and action, a structure is formed that supplies for each tree a means of resisting the storms. Such communities of trees, provided with ordinary roots, advance against and overcome enemies where singly they would perish in the conflict.


The Chigger.—Dr. H. M. Whelpley has published two papers on the chigger (Leptus irritans), an insect which is very troublesome to blackberry-pickers in the Mississippi Valley. It has no relation to the chigoe (Pulex penetrans) of South America, which resembles the fleas, while this insect is like the ticks. It is found in the Eastern and Southern States as well as in the Mississippi Valley, but has not been reported north of the fortieth degree of latitude, and does not seem to thrive in the far West. Besides human beings, it attacks the house-fly and is very troublesome to young fowls, where the parasites collect in lumps as large as a pin, and cause death, with the symptoms of poisoning by strychnine. Some persons are more susceptible to its attacks than others. Some specimens of the insect are almost transparent, but they all become darker in color as they become gorged with blood. Several remedies are prescribed for the living chiggers and for the sores they cause. Among them are kerosene and spirits of camphor.


Malays and Negritos of Malacca.—In his account before the Anthropological Institute of the races of the Straits Settlement (Malacca), Mr. Swettenham, of the Settlement's Civil Service, assumed that the Malays are not indigenous to the peninsula; but the exact place of their origin has not been established. According to their own traditions, they are of supernatural origin, and crossed over from Sumatra. Until about a. d. 1250 they were pagans or Hindooists, but near that time they came under the influence of Mohammedanism. The Perso-Arabian characters were introduced then, while the language had not previously been written. Relics of Hindoo superstition still exist among the Malays and Negritos of the peninsula, and customs that savor strongly of devil-worship. The author would classify