§ 13. It is strange that the mere alternation of the rent should give this effect; the more so, because alternate leaves, completely separate from each other, produce one of the most graceful types of building plants. Yet the fact is indeed so, that the alternate rent in the earth-leaf is the principal cause of its ragged effect. However deeply it may be rent symmetrically, as in the alchemilla, or buttercup, just instanced, and however finely divided, as in the parsleys, the result is always a delicate richness, unless the jags are alternate, and the leaf-tissue continuous at the stem; and the moment these conditions appear, so does the raggedness. § 14. It is yet more worthy of note that the proper duty of these leaves, which catch the eye so clearly and powerfully, would appear to be to draw the attention of man to spots where his work is needed, for they nearly all habitually grow on ruins or neglected ground: not noble ruins, or on _wild_ ground, but on heaps of rubbish, or pieces of land which have been indolently cultivated or much disturbed. The leaf on the right of the three in the Plate, which is the most characteristic of the class, is that of the Sisymbrium Irio, which grows, by choice, always on ruins left by fire. The plant, which, as far as I have observed, grows first on earth that has been moved, is the colts-foot: its broad covering leaf is much jagged, but only irregular, not alternate in the rent; but the weeds that mark habitual neglect, such as the thistle, give clear alternation. § 15. The aspects of complexity and carelessness of injury are farther increased in the herb of the field, because it is "herb yielding seed;" that is to say, a seed different in character from that which trees form in their fruit. I am somewhat alarmed in reading over the above sentence, lest a botanist, or other scientific person, should open the book at it. For of course the essential character of either fruit or seed being only that in the smallest compass the vital principle of the plant is rendered portable, and for some time, preservable, we ought to call every such vegetable dormitory a "fruit" or a "seed" indifferently. But with respect to man there is a notable difference between them. A seed is what we "sow." A fruit, what we "enjoy." Fruit is seed prepared especially for the sight and taste of man and animals; and in this sense we have true fruit and traitorous fruit (poisonous); but it is perhaps the best available distinction,[2] that seed being the part necessary for the renewed birth of the plant, a fruit is such seed enclosed or sustained by some extraneous substance, which is soft and juicy, and beautifully colored, pleasing and useful to animals and men.