314 IDEA OF NATURAL ARRANGEMENT. Endogens into close contact; besides breaking up the natural alliances of each, so as to scatter widely apart the members of groups nearly united. Examples of this will be hereafter given. 486. The Natural System, on the other hand, aims to present an harmonious and consistent view of the Vegetable Kingdom, by associating into Orders those genera which agree in the most numerous and important characters, and which differ from others in the same. A table of the characters of these Orders would therefore resemble the Table of Contents of a well-arranged book; giving at one glance to a person at all acquainted with the subject, an idea of the mode in which it is treated by the author, and of the relations which the several divisions of it had in his mind; and enabling a person who is entering upon the study of it, to do so with the knowledge that he is not gleaning at random, as if he were reading through a Dictionary, but that every acquisition he makes of an individual part is something toward an acquaintance with the plan of the whole. One more illustration may set this matter in a still clearer light. The reader may be requested to consider this series of Treatises as completed according to the original plan; and as consisting of a number of Volumes, each devoted to some particular Science, but all having a certain degree of connexion with each other. Each Volume consists of a series of Chapters, in which the subdivisions of these Sciences are respectively treated of, and among which there is a still closer degree of connexion. Every chapter, again, is made up of a number of paragraphs, each intended to contain one or more important facts, the knowledge of which is in itself useful, but which can only be fully understood when read continuously with the preceding and following paragraphs. We shall further suppose that the subject of every paragraph could be concisely expressed by a single word. Now we will imagine these paragraphs, all printed on separate slips of paper, with their appropriate titles, were given to a man of science with a request that he would arrange them for publication. His first idea might, perhaps, be, to place them in alphabetical order, so as to form a kind of Dictionary; this being the most easy method of fulfilling his task, and also having the advantage, IDEA OF NATURAL ARRANGEMENT. 315 when complete, of admitting very easy reference to any required subject. But what idea would the reader of such a volume gain, of the plan which the original Author had in his mind? Or what connected and harmonious scheme of knowledge could he frame from them, unless he digested and arranged them in his own mind, in the manner in which we shall suppose our Man of Science to proceed to do? He might commence in two ways;-either by separating the whole into heaps, according to the subjects to which they respectively refer, e. g. Mechanics, Chemistry, Geology, Botany, Zoology, &c. and then arranging these singly or by endeavouring to join the separate paragraphs together, according to their obvious connection. He will probably find a combination of these two methods the most advantageous; and by a careful examination of each single paragraph, in its relations to the whole, he may at last succeed in producing a series of connected Treatises, methodically arranged according to their respective subjects, and regularly divided into chapters, very nearly, or even exactly, upon the plan of the original Author. Now the Alphabetical arrangement would bear a close parallel with the Linnæan system of Botanical classification; whilst the latter distribution,— the one evidently most calculated to convey to the learner a connected rather than a desultory knowledge of the several objects of his pursuit, may not unaptly represent the Natural System. 487. It is by seeking for the latter only, that any of those general principles can ever be attained, which give their chief value to the facts of Science, and which lead us higher and higher in the contemplation of that Almighty Power and Boundless Wisdom by which the Universe was framed; for the Natural System would be but a Table of Contents of the Vegetable Kingdom, arranged on the plan of its Divine Author. In order to attain it, the Botanist requires to become acquainted, not only with all the tribes of Vegetables at present existing on the surface of the globe, but with the forms and characters of those which have once existed; since it cannot be doubted-all these constituted parts of the one general scheme, without the knowledge of which it would be impossible to reconstruct it. Now it is well known to the Botanist, 316 VALUE OF NATURAL SYSTEM. that a very large number of the species of Plants with which he is somewhat acquainted, have been so imperfectly examined and described, that their true place in the system cannot be determined; and there is good reason to believe that there are many more of which he is totally ignorant. Here, therefore, are abundant causes for the imperfection of any natural system which can be at present framed ; and should these ever be removed by long-continued labour and research, there will yet remain the other causes, resulting from the impossibility of becoming fully acquainted with the characters of the races which have existed in former periods of the earth's history, and have been swept completely from its face. Of these, some remains are occasionally discovered, sufficiently perfect to excite the liveliest interest and curiosity, by showing that races formerly existed, which fill up many of the wide gaps existing between those with whose characters we are now familiar, and which, if we knew more of them, would explain many things that are at present most perplexing. 488. Some of the strongest upholders of the Linnæan system are influenced by their veneration for its author; whose fame, however, will rest on a foundation much more durable than this. It is not generally known that the advantages of the Natural method have never been more highly appreciated, than they were by Linnæus himself. When he framed an Artificial system for the convenient arrangement of plants, it was with the very purpose for which the temporary employment of it has been here recommended,—namely, to facilitate that acquaintance with the Vegetable Kingdom, which must be gained before a Natural method can be framed. Linnæus himself gave a sketch of the Natural System, explaining the principles on which it might be expected to rest; and he pronounced the investigation of the natural affinities to be the great object of his studies, and the most important part of the science. He considered the Artificial system as a temporary expedient, which, however necessary at that day, would inevitably give place to the system of nature, so soon as its fundamental principles should be discovered. The elucidation of the latter, he said, is the first and ultimate aim of Botanists; to ATTEMPT BY LINNÆUS AT A NATURAL SYSTEM. 317 this end the labour of the greatest Botanists should be diligently directed; and the merest fragments of this system should be carefully studied. Though not then fully discovered, he spoke of the pursuit of it as held in high estimation by the wisest Botanists, and as being thought of little consequence only by the less learned. "For a long time,” he adds, "I have laboured to establish it; I have made many discoveries, but have not been able to perfect it; yet while I live, I shall continue to labour for its completion. In the mean time, I have published what I have been able to discover ; and whosoever shall resolve the few plants which still remain, shall be my Magnus Apollo. Those are the greatest Botanists, who are able to correct, augment, and perfect this method; which those who are unqualified should not attempt." Those therefore, who, priding themselves upon their being disciples of Linnæus, continue to employ his temporary and artificial system of classification, to the exclusion of one founded upon Natural principles, imagining that they are upheld by his authority, quite mistake the views of their great master, and sadly misrepresent his opinions. 489. The knowledge of the Vegetable Kingdom obtained by Linnæus, however, was far too small in amount, to enable him to frame a Natural System upon sound principles. The number of species known to him was probably not an eighth part of those with which Botanists are now acquainted; and no arrangement, therefore, could be formed, which was not marked by many wide and unsightly gaps. Further, so little was at that time known of the internal arrangement of the organs of plants, that even the distinction between the two principal forms of structure in the stem,evident and well-marked as it now appears,-was not then understood. Nevertheless, with that sagacity which so remarkably characterized him, Linnæus succeeded in grouping together genera into orders, which are even now regarded as, for the most part, very natural assemblages; that is, as containing plants really allied to each other in their most important characters, and differing from those of other orders in the same. But of the best mode of arranging these orders he was necessarily ignorant, since the most important characters were not then understood. The 318 PRINCIPLES OF NATURAL ARRANGEMENT. great progress which has been made since his time, in the Structural and Physiological departments of Botanical Science, has done much to place Classification on a more certain basis; yet there is still much wanting, before Botanists shall be generally agreed on the principles which shall regulate the division and subdivision of the Vegetable Kingdom. In the following outline, the object is less to give a bare sketch of the entire system, than to offer such a view of it, as may serve to show its nature. It is intended to describe most fully those Orders to which the greatest number of British Plants belong; and to state the relations which the species of most importance to man, whether as furnishing articles of food, valuable medicines, or materials for his various arts, bear to these. In so doing, it has been deemed advisable to adopt the Classification of De Candolle, that being the one which is most in use at the present time; and the principles upon which it is founded will, therefore, now be explained. 490. It may be remarked, however, in the first place, as a principle common to all Systems of Classification which profess to be Natural, that the different values which are attached to the various characters furnished by the several organs of plants, should be estimated by the degree in which they respectively indicate important similarities or differences of general conformation. It often happens that attention to one or two characters may afford a considerable amount of knowledge of the whole; because those characters are found to be inseparably connected with others. An instance of this has been already given, in regard to the primary division between Exogens and Endogens (§ 478.); and it may be useful to illustrate it further by reference to the Animal kingdom. If, for example, we meet with an Animal covered with feathers, we at once know a great deal of its internal structure and economy. It is a Vertebrated animal, possessing a jointed back-bone and complete internal skeleton; it has all five senses; its blood is red; it breathes air; its temperature is high; its young are produced from eggs; it walks upon two legs; &c. &c. Here we are at once informed that this unknown animal possesses all the characters peculiar to the class of Birds; since no other animals than Birds |