"The Vegetable Kingdom" and "The Botanical Register."
That John Lindley was a man of fine judgment is indicated by his own verdict that, except for The Vegetable Kingdom, The Theory and Practice of Horticulture was his best book. That verdict is sustained by posterity, as Mr Botting Hemsley declares of the former work,—"This grand book must be classed as Lindley's masterpiece. No similar English work was in existence in 1846 when the first edition appeared, nor was there in any language so encyclopaedic a work. Even now it is a valuable book in a small botanical library as it is a mine of information on points that are unchangeable. The work, as set forth in the preface, originated in a desire on the part of the author to make his countrymen acquainted with the progress of Systematical Botany abroad during the previous quarter of a century." Both in his books and in his lectures he adopted the natural system of classification and did much to popularise it though, as previously stated, his contemporaries Robert Brown, the Hookers, and G. Bentham were equally powerful adherents of the new system. To quote the picturesque if somewhat immoderate language of Reichenbach "for a long time the youthful interloper found no favour on account of his having introduced in conjunction Scot Brown, Gray and the still youthful Hooker the natural system of the hated Frenchman; where the more numerous disciples of Linnæus had thought to pass their lives in the glory of pondering and admiring the great Swede." That Lindley was an early convert to this innovation is also proved by the fact that his inaugural lecture at University College startled many by its frank and thorough expression of the superficial character of the artificial system of classifying plants.
The third and last edition of The Vegetable Kingdom consists of about 1000 pages in small type with upwards of 500 illustrations. It contains an historical review of the various "Natural Systems" which had been prepared, beginning with John Ray's (1703) and ending with his own, which is used in the work. In this system Lindley divided plants into seven classes:—Thallogens, Acrogens, Rhizogens, Endogens, Dictyogens, Gymnogens and Exogens, and each class was subdivided into alliances or groups of Natural Orders to which he gave names of uniform termination, as Algales, Filicales, Glumales, Malvales, etc. This classification, though ingenious, is defective, as the author himself recognised. Though never adopted by other writers this fact did not prevent Bentham and Hooker from citing Lindley's work frequently in their Genera Plantarum. As Mr Botting Hemsley observes, Lindley, who in all questions of classification was both cautious and modest, seems to have been an evolutionist without knowing it. Thus in the course of discussion on the permanency of species he observes that "all the groups into which plants are thrown are in one sense artificial, in as much as nature recognises no such groups. As the Classes, Natural Orders and Genera of botanists have no real existence in Nature, it follows that they have no fixed limits and consequently it is impossible to define them.... An arrangement then which shall be so absolutely correct an expression of the plan of nature as to justify its being called the Natural System is a chimera."
Owing to the fact that Hooker wrote the admirable and favourable review of the Origin of Species which appeared in the Gardeners' Chronicle, it has been inferred that Lindley himself was not very well disposed toward the new theories; but Lord Lindley states that his father was much impressed by the Origin, said it would revolutionise botanical studies but that there were difficulties which would require elucidation before Darwin's theory could be regarded as completely satisfactory—surely a perspicacious judgment.
To turn to the woodcuts of The Vegetable Kingdom affords both pleasure and relief—pleasure on account of their excellence, relief to escape from the monotonous prettiness of modern process work.
Though space will not allow reference to other text-books and to innumerable minor publications—many of which may be found in the Lindley Library in the Royal Horticultural Society's headquarters at Vincent Square—a brief mention must be made of the Botanical Register. This periodical was founded in 1815, and so early as 1823 Lindley became a contributor to it; but it was not till 1829 that his name appeared on the title-page. From that time he was sole editor till 1847, when the Botanical Register ceased to appear; unable doubtless to stand against the Botanical Magazine which under the editorship of Hooker had passed from a moribund state into one of remarkable vigour which now, 125 years after its foundation, it still enjoys.