Page:Popular Science Monthly Volume 67.djvu/594

588 or 'caulanthy' the terms meaning 'flower on the stem.' Caulanthy may often be seen in the tropics, while among trees of temperate regions it is almost unknown.

Plants inhabited by ants are sure to strike the attention of visitors. There are many of these so-called 'myrmecophilous' plants in the garden at Buitenzorg; some brought in from the neighborhood, while others, behaving like Topsy 'just growed.' The commonest are species of Myrmccodia, woody plants about two feet tall, with the base of the stem much swollen and containing large winding passages swarming with ants. These plants do not grow on the ground, but are attached

to the branch of some tree, a habit of life very common in moist climates. A handsome tree known as Humboldtia is also myrmecophilous. The flowering twigs are swollen and hollow—the cavity opening to the outer world by a small hole through which ants enter. Apparently in these various cases the ants do not serve the plants in any way. There are, however, certain species of Acacia, which produce a sweet substance attractive to a certain kind of warlike ants, and these ants protect the tree from the attacks of the leaf-cutting ants. Other kinds of Acacia, not provided with ant police, are often seriously damaged by the leaf-cutters.

In our school geographies we have all read about the wonderful banyan tree which sends down roots from its outspread branches and