Tropical Nature and Other Essays Author:Alfred R Wallace Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: caused by accident or decay, but repeated examination shows it be due to the natural growth of the tree. The accompanying outline sections of one of these trees ... more »that was cut down, exhibits its character. It was a noble Sections of trunk of a Bornean Forest-tree. 1. Section at seven feet from the ground. 2. 3. Sections much higher up. forest-tree, more than 200 feet high, but rather slender in proportion, and it was by no means an extreme example of its class. This peculiar form is probably produced by the downward growth of aerial roots, like some New Zealand trees whose growth has been traced, and of whose different stages drawings may be seen at the Library of the Linnean Society. These commence their existence as parasitical climbers which take root in the fork of some forest-tree and send down aerial roots which clasp round the stem that upholds them. As these roots increase in size and grow together laterally they cause the death of their foster-parent. The climber then grows rapidly, sending out large branches above and spreading roots below, and as the supporting tree decays away the aerial roots grow together and form anew trunk, more or less furrowed and buttressed, but exhibiting no other marks of its exceptional origin. Aerial-rooted forest-trees—like that figured in my Malay Archipelago (vol. i. p. 131)—and the equally remarkable fig-trees of various species, whose trunks are formed by a miniature forest of aerial roots, sometimes separate, sometimes matted together, are characteristic of the Eastern tropics, but appear to be rare or altogether unknown in America, and can therefore hardly be included among the general characteristics of the equatorial zone. Besides the varieties of form, however, the tree-trunks of these forests present many peculiaritie...« less