Page:An introduction to physiological and systematical botany (1st edition).djvu/88

 58 of plants, have justly acquired the name of trees. Yet, paradoxical as it may seem, they are rather perennial herbaceous plants, having nothing in common with the growth of trees in general. Their nature has been learnedly explained by M. Desfontaines, a celebrated French botanist, and by M. Mirbel in his Traité d'Anatomie et de Physiologie Végétales, vol. 1''. p. ''209, and Linnæus has long ago made remarks to the same purpose. The Palms are formed of successive circular crowns of leaves, which spring directly from the root. These leaves and their footstalks are furnished with bundles of large sap-vessels and returning vessels, like the leaves of our trees. When one circle of them has performed its office, another is formed within it, which being confined below, necessarily rises a little above the former. Thus successive circles grow one above the other, by which the vertical increase of the plant is almost without end. Each circle of leaves is independent of its predecessor, and has its own clusters of vessels, so that there can be no aggregation of woody circles; and yet in some of this tribe the spurious kind of stem, formed in the manner