But it is very difficult to tell whether these humble little herbs which live on the scraps that fall from the tall trees are either parasites or clients, which last do some good in return for their share. Probably they are distinctly useful and good for the forest if this is considered as a whole _establishment_. They use light which would otherwise be wasted, and their own dead leaves increase the annual deposit of leaf-mould. There are other plants, such as the Bird's-nest (_Neottia_) and Coralroot[143] Orchids, as well as Monotropa and others, which also live on the rich, decaying leaf-mould of forests, but these are generally pale in colour, for they possess but little green chlorophyll. They are more directly dependent on the mould and have ceased to do much work for themselves. Most of them in fact have entered into an alliance with fungi, and use these fungi to get their food material from the dead leaves. [143] In the first, the entangled underground stems and roots resemble a bird's nest; in the second, the peculiar red rhizomes are rather like coral. Such fungi are always abundant in good, well-grown forests (see p. 86). These Orchids and Monotropa have their roots and underground stems covered and wrapped round by the fungus threads, which extend from them in every direction, breaking up and decomposing the dead leaves. The colour of Monotropa is a pale waxen yellow, that of the others is usually a ghostly pale, opalescent, steel-blue or coral-like hue, which makes them very distinct in the dim, mysterious shades of the forest. These plants are undoubtedly of use, for they break up and decompose the leaf-mould. Another very interesting group are not well represented in this country. Sometimes one may see on an old tree a Gooseberry bush in full foliage quite high up the trunk in the fork of the branches. In sheltered woody ravines, Polypody ferns are often established on old moss-clad branches, where their green fronds hang over to catch as much as they can of the sunlight. But Orchids, Bromeliads, and Ferns which grow upon the branches of great trees are one of the most conspicuous and beautiful features of tropical woods. It is for these tree-orchids that the orchid-hunter braves the head-hunters of Borneo or traverses the precipices and rugged forests of Guatemala and Brazil. It is often necessary to cut down a tall tree in order to get the orchids in its higher branches. Often, however, this is unsuccessful, for the tree is so held up by creepers and other giants of the forest that it never reaches the ground! [Illustration: _Photo_ _Skeen and Co._ CINNAMON PEELING IN CEYLON]