THE PLANE. 685 



their position might be represented by two points of the compass, 

 north and south. This happens with the Hornbeam, Beech, Hazel, 

 Lime ; usually with the Chestnut, and often with the Birch. On 

 other trees the leaves are arranged spirally in the bud, so that if 

 our simile of the compass be applied their relative positions would 

 tall at some of the points intermediate between north and south, east 

 and west. The Fir, the Pine, the Larch, the Poplar, Willow, Elm, 

 and Alder ; the Oak, Walnut, Cherry, Apple, and Pear are examples 

 of this. 



These broad distinctions are made less simple by differences in 

 the ways the leaves touch one another, and the relative directions 

 in which they face. 



The way in which each separate leaf is folded in the bud, so 

 that it may occupy the least possible space, is of greater interest to 

 the general reader, because it affects the whole appearance of the tree 

 when first the young leaves are liberated from the bud. Some leaves, 

 such as those of the Lime, Ash, Oak, Cherry, and Hazel, are folded 

 at the central rib like a sheet of writing paper ; others are folded 

 like a fan, such as the Maple, Hornbeam, Sycamore, Beech, Birch, 

 and Wayfaring tree. Or again the leaves are neither crumpled nor 

 folded, but more or less curved to fit into the dome of the bud : the 

 Fir, the Pine, the Larch, Yews, Hollies, Willows, the Privet and the 

 Spindle tree are examples of this last class. 



Yet other questions suggest themselves. Do the leaves wholly 

 or partially overlap one another ? Do they lie with the central rib 

 in a line with the axis of the bud or twisted round it? So varied 

 and so complicated arc the methods by which the leaves find room 

 within the narrow bud-spaces ; yet it must be remembered that 

 each species has its own constant and unvarying plan. 



