ON WOOD AND PLANTATIONS. 
108 
of the peculiar expression of trees individually and in com 
position. The effect of a certain tree singly is often ex- 
ceedingly 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 infor- 
mation we shall offer a few remarks on the principal vari- 
eties of character afforded by trees in composition. 
Almost all trees, with relation to forms, may be divided 
into three kinds, viz. round-headed trees, oblong or pyra- 
midal trees, and spiry-topped trees ; and so far as the 
expressions of the different species comprised in these dis- 
tinct classes are concerned, they are, especially when 
viewed at a distance (as much of the wood seen in a 
prospect of any extent necessarily must be), productive ol 
nearly the same general effects. 
Round-headed trees compose by far the largest of these 
divisions. The term includes all those trees which have 
an irregular surface in their boughs, more or 
less varied in outline, but exhibiting in the 
^headed Trees d ~ whole a top or head comparatively round ; 
as the oak, ash, beech, and walnut. They are generally 
beautiful when young, from their smoothness, and the ele- 
gance of their forms ; but often grow picturesque when 
age and time have had an opportunity to produce their 
wonted effects upon them. In general, however, the dif- 
ferent round-headed trees may be considered as the most 
appropriate for introduction in highly- cultivated scenery, 
or landscapes where the character is that of graceful or 
polished beauty ; as they harmonize with almost all scenes, 
