XXXIX.-PRODROMUS FLORE NOVO-GRANATENSIS, OU ÉNUMÉRATION DES PLANTES DE LA NOUVELLE-GRENADE AVEC DESCRIPTION DES ESPÈCES NOUVELLES. Par MM. J. Triana et J. E. Planchon. Annales des Sciences Naturelles, ser. 4, vol. xvii. Botanique (to be continued and reissued as a separate publication). MÉMOIRE SUR LA FAMILLE DES GUTTIFÈRES. Par J. E. Planchon, D.M. et José Triana, D.M. Annales des Sciences Naturelles, ser. 4, vols. xiii to xvi., (reissued in a separate volume). Paris, 1862. THESE two papers are good examples of the two classes most to be recommended to partial workers in systematic botany, as useful contributions to science, although in different degrees-a critical enumeration of all the plants of a country, and a monograph of all the species of a group the one more practically useful to the investigator of the vegetable productions of the particular country referred to, the other always a much greater step in the advancement of science. Although one of them is as yet a commencement only, we here take them together as being by the same authors, the one having as it were grown out of the other. Both papers are distinguished by accuracy of observation and soundness of views, and illustrate well the comparative merits of each class of works.

Dr. José Triana, an active and intelligent young botanist, a native, as we believe, or at any rate a citizen of New Grenada, was employed in the chorographic expedition organized under the administration of General J. H. Lopez, and after six years of travel through the various provinces of that republic, he came over to Paris in 1857, for the purpose of determining the specimens he had collected, with a view to compiling, for the benefit of his countrymen, a popular work on the vegetable productions of their territory. The first inspection, however, of the herbaria of Paris and London showed him. how little was as yet really known of the vast botanical treasures of that luxuriant district of tropical America, and that a compilation was impossible for want of any scientific investigation on which it could be founded. He therefore changed his plan, and having secured the collaboration of Dr. Planchon, whose guidance as to the scientific portion of the work was essential, and having, after much negotiation, obtained the indispensable sanction and promise of support from the Government of his country, he set earnestly to work at a general Flora of New Grenada. For this he had excellent materials. Besides his own collections and those remitted to him by M. Linden, he had all those of the Herbarium of the Jardin des Plantes, where he worked, and he was enabled to borrow much from the herbaria of Delessert, De Candolle, Boissier, and Sagot. For the necessary consultation of books he was not so well off. The library of the botanical department of the Jardin des Plantes is confined to a few only of the systematic works in most common use, and although Delessert's Botanical Library, one of the richest known, is liberally open to all working botanists, the crossing half Paris every time a reference.

was to be verified was more than could be expected. Another drawback was the residence of his collaborator at Montpellier, at a distance of 500 miles from Paris, and away from any rich general herbarium. This entailed long correspondence and repeated delays, and when at length the first volume was ready for press, revolutions and civil wars stopped all supplies from the Government of New Grenada, and after years of alternate hopes and fears the completion of the great work originally contemplated was indefinitely postponed. The present Government, has, however, so far come forward as to enable arrangements to be made for the publication of the first volume at least in an abridged form, in the Annales des Sciences Naturelles, in detached portions, to be afterwards reissued as a separate work. This mode of publication, which the authors also adopted for the monograph of Guttifera, has the advantage of saving from pecuniary loss scientific labourers who can ill afford it; the chief inconvenience, independent of delay, is the impossibility of ascertaining the date of publication of new species in case of disputes as to priority, the Annales being habitually antedated, while the collected volumes are in a great measure post dated.

In substance this Prodromus Flore Novo-Granatensis is not an abridged synopsis for the use of residents or travellers in New Grenada, but a critical enumeration for the use of the general botanist who has a library at his command, for diagnostic characters are not given. The names of the published species are accompanied by such references, ascertained synonyms, or critical observations, as the earnest labours of Triana, and the extensive knowledge and sound. judgment of Planchon have enabled them to supply; the observations always given in the French language. The new and imperfectly known species are described in Latin, the descriptions being given in the nominative case where the species had been previously published, in the ablative case when new, a distinction of which we do not see the benefit. The ablative absolute was the form given by Linnæus to his diagnoses in which he expressed within the prescribed limit of twelve words the most striking or best contrasted characters of each species. These might be sufficient so long as the species of each genus or section were few and comprehensive. But as the number of species increased, and their variability became better known, diagnoses professing to include all absolute characters (i. e. all those without which a plant would not be conspecific) came to be more extended, the twelve words growing into more than as many lines, numerous alterations were introduced in order to admit all known varieties, until, in many recent works the description of all modifications in number, form, or structure, conventionally taken as absolute or essential characters has been introduced into the ablative diagnoses, and the nominative description has been reserved for little more than dimensions, colour, etc. supposed to be accessory only. There are some cases, however, where, within certain limits, dimensions and colour have proved more constant than form or number; accordingly

even those are now admitted into the ablative diagnoses, which, in Triana and Planchon's Flora for instance, only differ in general from descriptions in their inconvenient phraseology. It would be a great improvement in our modern systematic works, whether Floras or Monographs, if the Linnean restrictions on diagnoses were again enforced, including in them only the most striking, essential, or contrasted characters, under the distinct understanding that they are to serve as a guide only to the reader, who would then rely upon the detailed description in a more manageable nominative form, in broken sentences, for the absolute identification of his species.

At the conclusion of each natural Order a few lines are very usefully devoted to a sketch of the geographical relations of its NewGrenadine representatives, and the synonymy and critical observations are, as might be expected from so sound a botanist as Dr. Planchon, generally to be depended on so far as they go. But in this respect, as well as in specific affinities, completeness as to what is already known, and even in some cases accuracy, can only be attained by treating each species or group in succession monographically. It is for this reason that, with equal merits of authorship, the observations of the monographist always inspire greater confidence, and are therefore much more important than the passing criticisms of the enumerator of the plants of a collection, or of a district. The need of such a comprehensive research became particularly apparent to our authors when they came to Guttiferæ, of which they had much that was new to deal with. This Order is much more abundant within the tropics, than the comparatively scanty specimens we possess would lead us to suppose. The rigid succulent or gummy leaves, flowers, and fruit, are not tempting to ordinary collectors, who seek for showy plants, easily preserved. The specimens are, moreover, very apt to fall to pieces when dry, the flowers are often few and mostly dioecious, and thus complete and well-matched specimens of some of the commonest kinds are rare in herbaria. Guttiferæ had thus been generally neglected, or, with few exceptions, ill-defined and badly grouped. The new forms supplied by the New Grenada collections could not be determined without a revision of the genera next to which they should be placed, and Dr. Planchon's sagacity soon discovered the necessity of remodelling the whole system of their classification. In attempting this he found so much that was new and interesting in the varieties of floral structure and symmetry in species otherwise too closely allied to be generically separated, that he and his collaborator were induced to proceed to a detailed examination of every species of which they could procure specimens, and thus it was that the excellent and elaborate monographic memoir grew out of the enumeration they were preparing. And no work illustrates better the impossibility of determining a priori, whether a character first observed in a newly-discovered species is or not a good generic distinction. Their first impulse in determining M. Triana's novelties was to propose a number of new monotypic genera. In

their first general synopsis of the genera of the Order, they were induced to consolidate a few of these, as well as several similar ones, proposed by other botanists-and at length the careful examination of all the species made them hesitate about the distinctness of several more, which they had retained in their first general review. A still further consolidation has, in some instances, been proposed by Bentham and Hooker, in their Genera Plantarum, where they have in all essential particulars confirmed and adopted the views of Messrs. Planchon and Triana.

The striking peculiarity of Guttiferæ being the great diversity of structure in a very natural group, "variety in unity," as our authors express it, the difficulty of dividing it into tribes and genera was not, as in many other cases, to find characters, but to select them, and in this Messrs. Planchon and Triana have been eminently successful; they reject, as secondary, the placentation of the ovary and the nature of the fruit (as to consistence, dehiscence, &c.) and place still lower down the estivation of the floral envelopes and structure of the androecium, giving primary importance to the structure of the seed. It had long been known that the embryo of many Guttiferæ appeared in the form of a thick, hard, fleshy homogeneous mass, traversed, in some instances, by a linear distinct portion of a looser texture; on the other hand, two large fleshy, more or less distinct cotyledons had been observed in Calophylles; and in two different species of Clusia, two minute but distinct cotyledons at one end of the homogeneous mass had been pointed out by L. C. Richard and by Turpin, but overlooked by most subsequent authors. This gave rise to much discussion, whether the ordinary embryo of the Order must be considered as composed of two consolidated cotyledons, or of an albumen with a slender central embryo, or of an albuminous development of a central radicle, with minute or wholly aborted cotyledons. Dr. Planchon has shown that all these explanations are wrong if applied to all Guttiferæ, as there are, in fact, three distinct types of embryo. 1stly, An enormous apparently homogeneous radicle (rostellum, tigellus, or caulicle, of modern refined terminologists), with two small but distinct cotyledons at one end, and developing the root from the other end; 2ndly, An equally large radicle, traversed by a central pith, the cotyledons wholly aborted or so rudimentary as to be rather imagined than seen; and 3rdly, Two large fleshy cotyledons, with an exceedingly small radicle. These are taken as the essential characters of the three principal tribes, Clusieæ, Garcinies, and Calophylleæ. A few species, with a peculiar habit and style, are distinguished from Garcinieæ as a fourth tribe, under the name of Moronobeæ, and the anomalous genus Quiina is

220

*By some oversight, the detailed observations on the structure of the seed of the Calophylles are omitted in Messrs. Planchon and Triana's Memoir. In p. we are referred to the organographic part, where, p. 327, three types of Guttiferous embryos are spoken of, but only two described.

added as a fifth tribe. It might be objected, that the embryonic character is practically useless, as it is very rare to find seeds in herbarium specimens, and some might think that it wants verification, not having been ascertained in one-half, perhaps not in one-fourth, of the species known. But it has been ascertained in so large a proportion of the genera that we are justified in inferring its constancy; and, for practical purposes, it is accompanied by a combination of secondary characters, derived from the flower, which will readily guide us to the proper tribe, independently of the general facies peculiar to each. Thus, Clusieæ have distinct broad radiating stigmas, either sessile, or borne on distinct styles, the number of ovules in each cell of the ovary being variable; Moronobeæ have a single branched style, and always several ovules to each cell; Garcinieæ a single peltate stigma, and only one ovule to each cell ; and Calophylleæ an elongated single or branched style, and one, two, or four ovules to the whole ovary.

In form, the memoir is divided into two parts, systematic and organographic. The first portion is very detailed, and, as far as the genera are concerned, the form adopted is excellent, that of a short synopsis of contracted characters, and detailed descriptions under each genus. As to species, the new and little-known ones are carefully and accurately described, although, in some instances, multiplied beyond what our own experience would justify, and we regret to see that confusion we have already remarked upon between ablative and nominative descriptions, with nothing to guide the reader in the shape of short diagnoses or tabular synopses of contrasted characters. Several species also, supposed to be sufficiently known, are accompanied by references only to published works, without either character or description. This practice, generally pursued in many of the most valuable and elaborate French monographs (e. gr. in A. de Jussieu's admirable Memoir on Malpighiaceae) diminishes much their practical utility, inasmuch as it prevents the determining a plant without recourse to other works often too costly for the private library of a botanist, and the only advantage gained is the saving of a few pages of letter-press. The labour of adding a few characteristic lines to each of these species would be very little, the authors having necessarily verified the published descriptions of all the species. French botanists entertain, however, the idea that, by combining what might be (though falsely) taken for mere compilation with their original observations, they would diminish the scientific reputation of their work. This appears to us to be a great mistake. We cannot consider it any detraction from their personal glory to have combined practical usefulness with intrinsic merit.

The organological portion contains much that is deserving of study, especially as to the variability in some genera of characters, which, in other instances, are considered almost of ordinal importThe diversity of floral symmetry is much dwelt upon. Opposite decussate foliar organs with whorled or variously imbricate

ance.