Page:Popular Science Monthly Volume 39.djvu/351

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he pretends to know all about what one is showing him. His interest can be aroused only by objects the use of which is plain to him without explanation, or which he fancies have a market value. At them his eyes will shine with greed. Lack of self-confidence makes him suspicious, and his distrust appears in his look. His eyes will shine with his own rage, but no flame of noble indignation can be kindled in them on account of an evil deed or of a wrong of which he is the author.—Translated for The Popular Science Monthly from Das Ausland.



WHEN a plant in growing has reached a certain stage in its development, the character of the buds which have before produced branches changes, and flower buds appear. In correspondence with the change of character in the buds, the stem and leaves change also. The former becomes smaller and forms the peduncle of the flower, while the latter, dwindling from true leaves or foliage organs, become bracts, sepals, and petals.

The process of flowering is attended with very important results. While the plant has been growing rapidly, sending out new leaves and branches into the air and new roots into the earth, the total amount of material produced by general growth has not been expended. A certain portion is kept in reserve, and this is drawn upon when the time for flowering and fruiting has come. It is the exhaustion of this reserve of food which causes annuals to perish after perfecting their seed. In biennials a store of matter is laid up one year in the leaves or roots, to be drawn upon by the plant when the flowering time comes round the next year.

Lamarck, about seventy years ago, was the first to detect that a certain amount of heat was evolved on the expansion of the flowers of the European Arum. Their anthesis is equivalent to a burning up of some of the material of the plant. The heat so produced is sometimes quite considerable, and it can be measured by means of a thermo-electrical pile. A most notable example of the consumption of stored material is to be observed in the century plant. This grows for many years, laying up nourishment in its large, succulent leaves. After from fifteen to seventy years' growth the time for flowering comes; the reservoir of nourishment is drawn upon, the flower stalk is shot up with tremendous rapidity, and in a few weeks the thousand blossoms have opened, faded, and seeded. Then the whole plant dies. It has exhausted its store of nourishment, and consumed itself in the production of