Having now described the peculiar characteristics of these different classes of round-headed, spiry-topped oblong, and drooping trees, we should consider the proper method by which a harmonious combination of the different forms composing them may be made so as not to violate correct principles of taste. An indiscriminate mixture of their different forms would, it is evident, produce anything but an agreeable effect. For example, let a person plant together in a group, three trees of totally opposite forms and expressions, viz. a weeping willow, an oak, and a poplar; and the expression of the whole would be destroyed by the confusion resulting from their discordant forms. On the other hand, the mixture of trees that exactly correspond in their forms, if these forms, as in oblong or drooping trees, are similar will infallibly create sameness. In order then to produce beautiful variety which shall neither on the one side run into confusion, nor on the other verge into monotony, it is requisite to give some little attention to the harmony of form and color in the composition of trees in artificial plantations.