CLASSIFICATION OF TREES AS TO EXPRESSION. The amateur who wishes to dispose his plantations in the natural style of Landscape Gardening so as to produce graceful or picturesque landscape, will be greatly aided by a study of the peculiar expression of trees individually and in composition. The effect of a certain tree singly is often exceedingly different from that of a group of the same trees. To be fully aware of the effect of groups and masses requires considerable study, and the progress in this study may be greatly facilitated by a recurrence from groups in nature to groups in pictures. As a further aid to this most desirable species of information we shall offer a few remarks on the principal varieties of character afforded by trees in composition.