Muscos et Algas itemque Arbores Coniferas, et denique America Filices. Idem summum providumque Numen hæc quoque plantarum genera in dicta distribuit climata, pro variâ soli naturâ, in Alpibus montibus, campis, pratis, agris, paludibus, aquis, etc., quo in suo quodque natali loco lætius cresceret et floreret. Qui veram cunque et solidam plantarum scientiam aucupatur, patriam ipsarum ac sedem cujusque propriam, haud sane ignorabit. Sic qui in communi vitâ, in usum œconomicum illas vel medicum convertere velit, ubicunque gentium et locorum habitent, probe sciat, necesse est, etc.

Humboldt's "Aspects of Nature," ("Ansichten der Natur,") and his "Essai sur la Géographie des Plantes, accompagné d'un Tableau Physique des Regions Equinoxiales, Paris, 1807," gave such an impulse to botanical geography and geographical botany, that he is usually considered to be the founder of this department of science, although he was not the first author who wrote on this subject. Humboldt's "Essai" has been translated into English and other European languages; and its favourable influence may be traced in almost all works on physical geography subsequently published-such as Schouw's "Grandzüge einer Allgemeinen Pflanzengeographie," Berlin, 1823; Beilschmied's "Pflanzengeographie," Breslau, 1831; Meyen's "Grundriss der Pflanzengeographie," Berlin, 1836; Grisebach's "Berichte über die Leistungen in der Pflanzengeographie," Berlin, 1844-56.

Rudolph refers to these works as his sources of information; but he has overlooked the most recent and the most important publication on plant-geography-viz., the "Geographie Botanique Raisonée, ou Exposition des Faits Principales et des Lois concernant la Distribution Géographique des Plantes de l'Epoque Actuelle. Par M. Alph. Decandolle." Two volumes. Paris, 1855.

Plant-geography having been established by such works as we have quoted, it followed, as a natural consequence, that other books were produced in order to popularise the new science, so as to introduce it into schools, and to render it attainable in private life without much preparatory study. This was the object of several popular lectures delivered and published by Schleiden. The same popularising aim predominates in the following publication by the father of a lamented traveller: Vogel's "Naturbilder," Leipzig, 1846; and in Schouw's "Die Erde, die Pflanzen und der Mensch," Leipzig, 1851; and in the "Atlas der Pflanzen-geographie," von L. Rudolph. Berlin, 1852. The work at present under review is the text-book explaining this Atlas which the author published seven years earlier, aiming to popularise the science of geographical botany. Mr Ludwig Rudolph saw that even in the better schools, numerous particulars are taught without showing their relation to a general unity: "Es fehlt unserm Unterricht zu oft die Beziehung des Einzelnen auf das

Ganze, die Erweiterung der Aussicht die hinter dem vorliegenden Gegenstande der Betrachtung die ganze Fülle ähnlicher Erscheinungen ahnen läszt, die dem Gemüthe Befriedigung, der Phantasie Nahrung giebt und den Eifer zum Weiterforschen anregt." This defect is in some degree remedied by geographical botany, which looks upon the whole vegetative covering of our globe as being one connected whole. In doing so, geographical botany directs our attention especially to those plants which give to a whole country its characteristic physiognomy, leaving to systematic botany the office of arranging plants laboriously in classes, subclasses, orders, families, genera, species, and varieties. In systematic botany the analytical, and in phyto-geography the synthetical, efforts predominate. However, let it be remembered, that analysis and synthesis can be kept widely asunder only in the abstract, and that in reality the phyto-geographer must be trained by systematic botany for accurately observing plants.

The pleasure which we derive from the contemplation of the vegetable creation in forests, fields, and meadows, is, in its indefinitiveness, similar to that from instrumental music. The vague sensations created by instrumental music assume more definiteness when harmonising vocal music is added. So also the pleasurable but vague sensations arising from the contemplation of nature are raised to definiteness when the beholder becomes conscious of their importance by the interpretations offered in botanical geography. Systematic botany may be compared with acoustics, giving an account of all sounds. A merely sensuous delight in forests, fields, and meadows is like revelling in instrumental sounds, the pleasure in which is much augmented by a knowledge of thorough bass, which enables us to adapt the human voice so as to indicate the meaning, aim, and intention of the sounds with which it acoustically and mentally harmonises. Nature speaks to us and to all men, but it gives an uncertain sound, and becomes intelligible only when man interprets it in words. Nature, like music, requires the mouth of man to render it fully enjoyable, by giving utterance to its meaning.

Systematic botany, in classifying plants, separates the groups in which they naturally grow, and severs from the isolated plant its organs of fructification, which again are pulled to pieces in order to submit minute portions to the microscope, aiming to establish divisions and subdivisions of the Systema Plantarum. But the plant-geographer does not cut down any plant, and does not pull flowers asunder, because he has not to systematise, but to consider the influence of climate upon plants generally, and also the reaction of plants upon climate. Systematic botany has to consider chiefly some minute portions of the sexual organs of propagation, while the plant-geographer attends more to the massive portions of plants giving character to the scenery of

countries; consequently the organs of nutrition and preservation are to him of more importance than those of generation, unless taken in the mass. Systematic botany endeavours to know 200,000 species of plants, which are all nearly of the same systematic importance. But a small number from this host are selected by the plant-geographer-viz., those which sensibly affect the weal and woe, the comfort and enjoyment of man-and for which he has never to search, because they stare him boldly in the face, being so massive, either in themselves or by their aggregation, that they cannot be overlooked.

Plant-geography takes its isothermal, isotheral, and isochimenal lines from physical geography, but considers them, as also the events explained in meteorology, in their effects upon vegetation.

We highly approve of the manner in which Mr Rudolph advocates the importance of phyto-geographical studies, and of the correct conception of their general aim and limits; but in the execution of the work, we find some defects and errors which should not have been transmitted to a second edition. Having been honoured by the King of Prussia with a gold medal for his "Phyto-geographical Atlas," certainly the printed pages of the "Text Book" should not be in contradiction with themselves and with known facts.

On page 446, we find the words of the text, "Die chilenische araucaria" at the foot of the page explained by "Araucaria excelsa." But this is a mistake; because the A. excelsa comes from Norfolk Island, and the A. imbricata from Chili. It seems that the word "Aronswurzeln," on page 432, means Arrowroot. The author should have translated "Pfeilwurzeln," if he would translate a name almost received into German ; but to put "Aron" instead of "Arrow," creates confusion. A more important error than mere misnomers occurs on page 40. L. Rudolph repeats, undoubtedly on the authority of some scientific works-"Die Europæische Zwergpalme Chamaerops humilis, die in der Barbarei als dichtes Gebüsch erscheint. findet sich am ganzen

Mittelmeer." This is a geographical mistake. Chamaerops humilis, which abounds on the western shores of the Mediterranean, on the Barbary coast, and in Spain, is, for causes which pläntgeography should endeavour to discover, on the eastern shores either entirely wanting, or very scarce. The writer of this review has not met with it in Egypt, nor in Palestine, nor in Syria, nor about Smyrna, nor about Constantinople, nor in Zante, nor in Corfu, nor about Trieste, nor in Lussin Piccolo, nor in Meleda, nor at Athens, nor in Morea, nor in Ægina, nor in Syra. Therefore we deem it wrong that the error should be constantly transcribed from one geographical work into the other. Certainly a traveller cannot vouch for the impossibility of finding Chamarops

humilis in some secluded spots rarely visited on the eastern shores of the Mediterranean. But even in case that it could be found, the scarcity of so large a plant would require explanation, while the same palm covers, in Barbary and Spain, extensive tracts of country, whose climate and soil are similar to those of the eastern shores of the Mediterranean, where Chamaerops humilis is wanting. Such glaring errors make us doubtful about other statements of the author-e. g., when he tells us of "oranges ripening in the south of England in the open air as wall-fruit." (P. 354.)

The stereotyped error of Chamaerops humilis being spread over all the Mediterranean coasts affects some of the most interesting phyto-geographical inquiries which were reported by Ch. Martins in the Revue de deux Mondes, as early as 1856, in a paper sur la Géographie Botanique et ses progrès :

"Le palmier nain (Chamaerops humilis) existe dans le midi dų Portugal, dans toute la partie meridionale et occidentale de l'Espagne, il manque dans le Roussillon et le Languedoc, la Corse et le nord de la Sardaigne, mais apparait sur un espace restraint de la côte de Nice et à l'ile de Capraia près de Livourne; puis il manque de nouveau dans tout le nord de la péninsule italique; il ne reparait qu'aux environs de la Terracine, sur les limites du royaume de Naples et des états du pape, devient commun dans l'île de Caprée et surtout dans Sicile. Dans la partie orientale de la péninsule italique il se trouve à Tarente, puis en face de la Dalmatie ou il descend jusqu'au golfe de Corinthe, mais il n'existe n en Grèce ni dans les îles de Zante et de Corfou. Trop commun en Algérie, où il est le plus grand obstacle aux défrichemens, on ne le rencontre pas en Egypte mais seulement en Nubie. Aucune consideration géologique ou météorologique n'explique une distribution aussi singulière. Pourquoi le palmier nain manque-t-il dans la Corse et dans la partie septentrionale de la Sardaigne, tandis qu'il se trouve au nord près de Nice, à l'est dans la petite île de Capraia, à l'ouest sur toute la côte d'Espagne ? D'anciennes connexions de terres séparées maintenant par la mer peuvent seules rendre compte de cette dispersion capricieuse."

Since October 1856, when this was published, the old phytogeographical error as to Chamaerops humilis has been so often repeated even by good authors, that we must try whether the Philosophical Journal will eradicate it finally. A plant marking the limits between the region of palms and of laurels is of so much phyto-geographical importance, that erroneous conjectures should yield to true observation, which in this instance is not difficult; for even those who run may read the fact, that phytogeography is still in its infancy, and that no science would be more advanced than this by a well-organised universal scientific congress, not attempting impossible acclimatisation, but realising most important naturalisations, or at least translocations, like NEW SERIES.-VOL. XI. NO. II.-APRIL 1860.

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that of the maize and the potato. It belongs to the duties of periodical literature to prevent the spreading of the phyto-geographical errors of great authors-e. g., Barth was mistaken when he wrote about Borassus Alabelliformis in Central Africa. He saw probably Borassus Æthiopum. Livingstone was mistaken when he reported about Cinchona in South Africa. In the magnificent Historia Palmarum by Martius, we find the following inaccurate statement about Chamaerops humilis: per maximam partem littorum Maris Mediterranei diffusa offenditur, while in fact it is scarcely one-fourth of these coasts where this palm occurs. By inaccurate translators has even the limitation maximam partem been omitted.

Mr Rudolph commits another mistake, informing us that Ilex Aquifolium or holly, growing in more favourable spots of Europe to the size of a tree, occurs in England only as a shrub. The fact is, that we see Ilex Aquifolium even at Aberdeen forming trees, and the climate of Britain seems more favourable to holly than that of Germany. It is not to be wondered at that, along with such mistakes committed in Europe, there should be mentioned Cinchonenwälder auf den Bergen der Tropen, p. 46 (cinchona forests on tropical mountains). There do not exist any cinchona forests, but only primitive forests, in which, densely surrounded by other trees, some cinchonas are interspersed, which cannot be reared alone after the surrounding thicket of the primæval forest has been destroyed. It would also have been well to tell us what kind of cinchona trees Mr Rudolph mentions as belonging to the flora of Hawaii, and on what authority he does so on page 218. He has told us before, on page 202, that Cinchona condaminea is confined to a narrow spot in Peru, about the fourth degree of latitude, and to an elevation from 5000 to 7000 feet. He repeats also sometimes the inaccurate term Chinawälder (cinchona forests), and seems to be unacquainted with the researches of Weddell, Delondre, Ilasskarl, and others, who have proved that there are no such forests, but only cinchona interspersed among other trees of the primeval forest, and have shown the limits in which the cinchona trees grow with much greater accuracy than Mr Rudolph lets us suppose. Botanists, speaking of the genus Cinchona, mean the various species of the trees from which Jesuit's or Peruvian bark is obtained, and not the order of Cinchonacea to which the Coffea Arabica also belongs. Evidently there is in the following statement some error, page 217: Die mittlere jährliche Wärme von Kanton beträgt 17° 5′; die mittlere Sommerwärme 22° 2′; die mittlere Winterwärme, 21° 1′; and in den Sommermonaten fällt selbst bei Nacht die Temperatur selten unter, 22° !!* This is quite impossible, because the mean temperature of winter cannot be above the mean

*The degrees are Reaumur's.