§ 15. You may thus regard the whole tree as composed of a series of such thick, flat, branch-leaves; only incomparably more varied and enriched in framework as they spread; and arranged more or less in spirals round the trunk. Gather a cone of a Scotch fir; begin at the bottom of it, and pull off the seeds, so as to show one of the spiral rows of them continuously, from the bottom to the top, leaving enough seeds above them to support the row. Then the gradual lengthening of the seeds from the root, their spiral arrangement, and their limitation within a curved, convex form, furnish the best _severe_ type you can have of the branch system of all stemmed trees; and each seed of the cone represents, not badly, the sort of flattened solid leaf-shape which all complete branches have. Also, if you will try to draw the spiral of the fir-cone, you will understand something about tree-perspective, which may be generally useful. Finally, if you note the way in which the seeds of the cone slip each farther and farther over each other, so as to change sides in the middle of the cone, and obtain a reversed action of spiral lines in the upper half, you may imagine what a piece of work it would be for both of us, if we were to try to follow the complexities of branch order in trees of irregular growth, such as the rhododendron. I tried to do it, at least, for the pine, in section, but saw I was getting into a perfect maelström of spirals, from which no efforts would have freed me, in any imaginable time, and the only safe way was to keep wholly out of the stream. [Illustration: FIG. 54.] § 16. The alternate system, leading especially to the formation of forked trees, is more manageable; and if the reader is master of perspective, he may proceed some distance in the examination of that for himself. But I do not care to frighten the general reader by many diagrams: the book is always sure to open at them when he takes it up. I will venture on one which has perhaps something a little amusing about it, and is really of importance. [Illustration: FIG. 55.] [Illustration: J. Ruskin J. Emslie 56. Sketch by a Clerk of the Works.]