3. Civic lessons reflected in trees: The community life of trees in the grove, their growth, struggles for light and food and their mutual aid can be brought out and compared with the community life among people. The trees may here be seen struggling with each other for light and food, forcing each other's growth upward, some winning out and developing into stalwart and thrifty specimens and others becoming suppressed or entirely killed. On the other hand they may be seen helping each other in their community growth by protecting each other from windfall and by contributing to the fertility of the forest soil in dropping their leaves and shading the ground so that these fallen leaves may decompose readily. [Illustration: FIG. 154.--Trees also Grow in Communities.] 4. Enemies of trees: An old stump or tree may be seen crumbling away under the influence of fungi and here the children may be shown the effects of tree diseases both as destroyers of life and as up-builders, because fungi turn to dust the living trees and build up others by furnishing them with the decomposed wood matter. Insects too, may be invading the old dead tree, and something of their nature, habits and influences may be gone into. They may be shown as wood borers, leaf eaters, or sap suckers, all injurious to the tree. On the other hand they may be shown as seed disseminators and as parasites on other injurious insects; all benefactors. Forest fires as an enemy of trees might be touched upon by noting how easily the leaves may be ignited and a surface fire started when the season is dry. Top and ground fires emanating from surface fires can then be readily explained. [Illustration: FIG. 155.--Trees Blend Together to Form a Beautiful Composition.] 5. Expression: The pupils have by this time been taught to feel the beautiful, to observe carefully and to reason intelligently and they may now be trained to express themselves properly. This may be accomplished by asking them to remember their observations and to write about them in the classroom. The lesson may be supplemented with effective reading about trees and forests. Interesting reading matter of this sort can be found in abundance in children's readers, in special books on the subject and in Arbor Day Manuals published by the various State Education Departments. 6. Preparation: In order to save time looking for objects of interest and for the purpose of correlating the various observations so that all will follow in orderly sequence, it is well for the teacher or leader to go over the ground beforehand and note the special features of interest. The various topics can then be given some thought and a brief synopsis can be drawn up to serve as a memorandum and guide on the trip.