15. Illustration. Thus in magnitude, although the tiny moss is far removed from the gigantic oak, yet a series connects them representing every imaginable intermediate grade in size. So in number, from the one-stamened saltwort to the hundred-stamened rose, there is a connecting series, representing every intervening number. Moreover, in form and figure, we pass from the thread-leafed pine to the broad-leafed poplar through a series of every intermediate degree of leaf-expansion; and from the regular-flowered crowfoot to the distorted monks-hood by a series graduated in like manner.
16. Natura non saltus facit, said Linnaeus, in evident allusion to this beau-tiful principle, which will constitute one of the most interesting themes of botanical study.
17. Accomodated Forms or organs is a phrase applied to another principle in the Divine plan, the reverse of the first. This principle appears in the adaptation of different organs in different species to one common use; of which there are many familiar
18. Examples. Thus, the slender vine requires support. Now it throws out a tendril for this very purpose, grasping whatever object it may reach, as in the grape. Again, the prolonged leaf-stalk answers the same end, as in Clematis. Again, the supple stem itself, by its own coils supports itself, as in the hop; and, lastly, adventitious rootlets in the ivy.
19. Another illustration. Reproduction is the general office of the seed; but this end is also accomplished, in different species, by nearly every other organ, by buds, bulblets, bulbs, tubers, cuttings, scions, and even leaves.
20. Another. This principle is also traced in the nutritious deposits of plants, which are generally made in the fruit; but often the root serves as the reservoir instead, or even the stem. And in case of the fruit, the rich deposit is now found in the pericarp of the peach, the calyx of the apple, the receptacle of the strawberry, the cotyledons of the almond, the bracts, flower-stalks, etc, of the pine-apple. Thus God's boundless resources of skill can accomplish either one purpose in a thousand different ways, or a thousand different purposes by a single organ.
21. Arrested Forms. This principle, demanding a wider range of generalization than either of the foregoing, we state rather as a hypothesis, that the student may hereafter test its probability by his own observations. The flowering plants which clothe the earth in such numbers, constituting the apparent vegetable world, are in truth but a minor part of it in respect to numbers. Numerous tribes, of lower rank, embracing thousands of species, reach far down the scale, beyond the utmost limits of the microscope. Now a principle of analogy seems to pervade these ranks, called the principle of arrested forms, binding all together in one consistent whole, proving that for the vast realm of vegetation there was but one plan and one origin
22. The Hypothesis stated. The successive tribes of vegetation, beginning with the lowest, have each their type or analogue in the successive stages of em* bryonic growth in the highest tribe.
23. More explicitly: the flowering plant, in the course of its growth from the pollen grain to the completed embryo, passes necessarily through a series of transient forms. Now, suppose the development of the plant arrested at each of these stages, so that these transient forms become permanent, we should have a series of organisms analogous to the various tribes of Flowerless Plants; the Pro-tococcus, e. g., an arrested pollen grain; the Oscillaria, an arrested pollen tube; and so on up to the Marsillea, whose organization answers to that of the full-formed embryo of the flowering plant. Thus we might truly say of the lower plants that they are the arrested forms of the higher.
24. Individuality of the Plant. The plant is both material and immaterial, Its form and substance is the material, its life the immaterial. The material commences existence as a single cell, and is ever changing. The immaterial gives to that cell its individuality, and fixes inevitably its law of development, so that it must grow up to become such a plant as it is, and by no possibility any other.
25. Illustration. The embryonic cell of arose may not differ materially, in the least, from that of the grape: but the individuality of each is widely different This principle in the one will make it a rose; in the other, a grape. Individuality can not be predicated of a stone.
26. Life and death are equally predicated of the plant. The latter follows close upon the former, with unequal, inevitable step, and soon disputes possession in the same living fabric. The plant both lives and dies at once. Life passes on from cell to cell, and in the parts which it has abandoned dissolution and decay are soon manifest. Thus the whole existence of the individual is a contest. Life advances, death pursues, and ultimately triumphs. But not so in the species. Securely transferred to the seed, the living immaterial plant mocks the destroyer, and begins its career anew, multiplied a hundred fold.
27. The seed of the plant is its redemption. Through this appointment, the conquest of death is apparent, while the triumph of life is real. In the " grain of mustard" there is literally & faith - an energy which will raise it from the dust, " a tree." Yet, as in the wheat and all other seed, "it shall not be quickened except it die." Hence,
28. Plants may teach us lessons in sacred things. While we study the facts and the forms of the vegetable world, we should also aim to learn the purposes accomplished, and the great principles adopted in its creation. We should also learn to recognize here the tokens (too long overlooked) which declare that nature sympathizes with humanity in the circumstances of the Fall, the Redemption, and the Life. Such study alone is adapted to acquaint us with the thoughts of the intelligent Creator, and to discipline aright the mind which was created in His image.
29. Botany combines pleasure with improvement. It conducts the student into the fields and forests amidst the verdure of spring and the bloom of summer; to the charming retreats of Nature in her wild luxuriance, or where she patiently smiles under the improving hand of cultivation. It furnishes him with vigorous exercise, both of body and mind, which is no less salutary than agreeable, and its subjects of investigation are all such as are adapted to please the eye, refine the taste, and improve the heart.