THE STORY TOLD BY FOSSIL PLANTS
The long procession of changing forms has not yet come to a halt, and man, having learned some of Nature’s methods, has so applied them as to produce marvellous new varieties of flower and fruit, new habits of growth, and new adaptability to environment.
We have seen in our brief survey of the floras of the past that they illustrate the evolutionary principles set forth. We observe a gradual transformation from simple and generalized to complex and specialized forms. We see different groups becoming specialized in various ways and attaining dominance for a time, and eventually we see those that were less perfectly adapted to survive going down in competition with those that were more perfectly adapted. At one time it may be the Palaeozoic club mosses, whose trunks were mechanically defective as compared with the trunks of the contemporary exogenous conifers. At another time we see the seed ferns, with their large and complex seeds, replaced by plants having simpler and more efficient seeds. In one way or another the story repeats itself through millions of years of history.
REFERENCES
- Berry, Edward W. Paleobotany: A Sketch of the Origin and Evolution of Floras. Smithsonian Institution, Ann. Rept. for 1918, pp. 289–407, 1920.
- Berry, Edward Wilber. Tree Ancestors. A Glimpse Into the Past. Williams & Wilkins Co., Baltimore, 1923.
- Knowlton, Frank Hall. Plants of the Past. Princeton University Press, 1927.
- Scott, Dunkinfield Henry. Studies in Fossil Botany. 3rd ed., 2 vols. A. & C. Black, London, 1920–1923. Extinct Plants and Problems of Evolution. Macmillan & Co., London, 1924.
- Seward, A. C. Fossil Plants. 4 volumes. Cambridge University Press, 1898–1919.
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