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piration of all who are interested in the ed-| Göppart and Unger on the Continent, and ucation and moral wellbeing of their towns- by Dawson in Canada · has received very important accessions of late through the untiring energy of Mr. Binney, of Manchester, who has devoted nearly thirty years to the search for those rarely-found specimens which exhibit the internal structure of the plant. His elaborate description of the most abundant and, till his researches, the least-understood plant of the coal measures, calamites, has just appeared in the memoirs of the Palæontographical Society; and some of Mr. Binney's materials having also formed the subject of a very recent and valuable paper by Mr. Carruthers, of the British Museum, I may quote their joint results as one. These show that calamites is an actual member of the existing family of Equisetacea which contained previously but one genus-that of the common mare's-tails of our river-banks and woods; as also that nearly a dozen other genera of coal-measure plants may be referred to it. This affinity of calamites had, indeed, been guessed at before, and the genus now referred to it, having been founded on mere fragments, were always doubtful; but the value of these positive identifications is none the less on these accounts. It may hereafter prove of some significance that these calamites — which in the coal epoch assumed gigantic proportions and presented multitudinous forms and very varied organs of growth — are now represented by but one genus, differing most remarkably from its prototype in size and the simplicity and uniformity of its vegetable organs.
My remarks on the British Museum convey no reflection on the able officers who have in so short a time formed this wonderful collection. The late Mr. Lawrence, in his lecture in 1815, congratulates his audience on the formation of a geological collection having been just determined upon. In 1838, when I first knew the Museum, in Old Montague House, I was told it ranked about the sixth in Europe; now, and for some years past, it has been considered to be the finest in the world. This is due to the energy and ability of the keepers and curators; and, in mentioning them, I would wish to pay a passing tribute to the merits of the venerable Dr. Gray, who has devoted his life to the development of the Geological Department with a singleness of purpose, liberality and zeal beyond all praise. At the time when Old Montague House contained the national collections there was but one museum in the metropolis in which the naturalist could study to much purpose; this was the Hunterian (of the Royal College of Surgeons), then under the superintendence of the late Mr. Clift and of Prof. Owen, the friend of my early youth, when preparing myself to accompany the Antarctic expedition, and who instructed me in the use of that now unrivalled series of catalogues that owed so much to himself. From the Museum of the Royal College of Surgeons the national and provincial museums of England have much to learn and to copy, and, thanks to the munificence of the Council of the college, and to the zeal and ability of the present conservator, Mr. Flower, it retains the position it attained thirty years ago, of being the best and richest institution of the kind in Europe. In my own special science the greatest advances that have been made during the last ten years have been in the departments of Fossil Botany and Vegetable Physiology. In the past history of the globe two epochs stand prominently out the carboniferous and the miocene- - for the abundant material they afford and the light they throw on the early conditions of the vegetable kingdom. Why plants should have been so much more lavishly preserved during these than during some of the intervening or earlier epochs we do not rightly know; but the comparative poverty of the Floras of the latter is one among the strongest evidences of the imperfection of the geological record. Our knowledge of coal plants—which since the days of Sternberg, Brongniart, and Lindley and Hutton, has been chiefly advanced by
Passing to the tertiary times, the labours of Count Saperte in France, of Gauden and Strozzi, and of Massolonghi in Italy, of Lesquereux in America, and, above all, of Heer in Switzerland, have, within the last ten years, accumulated vast numbers of species of fossil plants; and if the determination of the affinities of the majority are trustworthy, they prove the persistence throughout the tertiary strata of many interesting families and genera, and the rarity fothers than these. Here, however, much value cannot be attached to negative evidence. Almost the only available materials for determining the affinities of the vast majority of these tertiary plants are their mutilated leaves, and, unlike the bones of vertebrate animals and the shells of molluses, the leaves of individual plants are extremely variable in all their characters.
Furthermore, the leaves of plants of different natural families and of different countries mimic one another to such a degree that, in the case of recent flowers, every botanist regards these organs as a most treach
erous guide to affinity. Of the structural characters which are drawn from the internal organs of plants, and especially from their fruit, seeds and flowers, few traces are to be found in the fossils, and yet it is from them exclusively that the position of a recent plant in the vegetable kingdom can be certified.
that an arboreous vegetation once extended to the Pole itself. Discoveries such as these appear at first actually to retard the progress of science by confounding all previous geological reasoning as to the climate and condition of the globe during the tertiary epoch.
I have said that the greatest botanical An instructive instance of over-reliance discoveries made during the last ten years on leaves, and perhaps, too, on unperceived have been physiological, and I here alluded ideas, happened not long ago to a palæonto- especially to the series of papers on the ferlogist of such distinguished merit that his tilization of plants which we owe to Mr. reputation cannot suffer from an allusion to Darwin. You are aware that this distinit. In the course of his labours over some guished naturalist, after accumulating stores imperfect specimen from a most interesting of facts in geology and zoology during his locality, he referred these associated impres- circumnavigation of the globe with Capt. sions of fossil leaves to three genera, belong- FitzRoy, espoused the doctrine of the coning to as many different families of plants, tinuous evolution of life, and, by applying and was thus helped to what would have to it the principles of natural selection, been some important conclusions as to the evolved his theory of the origin of species. vegetation of the period in which they were Instead of publishing these views as soon deposited. A subsequent observer, who as conceived, he devoted twenty more years was a botanist, but not a paleontologist, declares these three supposed genera to be the three leaflets of one leaf of one plant, and this the common blackberry, which still grows on the spot. Which of the two is right I do not say; the fact shows to what opposite conclusions different observers of the same fossil materials may be led. In this most unreliable of sciences, fossil botany, we do but grope in the dark; of the thousands of objects we stumble against we here and there recognize a likeness to what we have elsewhere known, and rely on external similitude for a helping hand to its affinities. Of the great majority of specimens we know nothing for certain, and of no small proportion we are utterly ignorant. If, however, much is uncertain, all is not so, and the science has of late made sure and steady progress, and developed really grand results. Heer's labours on the miocene and pliocene Floras, especially, are of the highest value and interest. His conclusions regarding the flower of the Bovey Tracy coalbeds (for the publication of which in a form worthy of their value and of their author's merit we are indebted to the wise liberality of Miss Burdett Coutts) are founded on a sufficient number of absolute determinations: and his more recent Flora Fossils Arctica' threatens to create a revolution in tertiary geology. In this latter work Prof. Heer shows, in apparently unassailable evidence, that forests of Austrian, American and Asiatic trees, flourished during miocene times in Iceland, Greenland, Spitzbergen, and the Polar American Islands, in latitudes where such trees could not now exist under any conceivable conditions or positions of land or sea or ice, and leaving little doubt but
tò further observation, study, and experiment, with a view of maturing or subverting them. Among the subjects requiring elucidation or verification were many that appertained to botany, but which had been overlooked or misunderstood by botanical writers, and these he set himself to examine vigorously. The first fruits of his labours was his volume on the Fertilization of Orchids,' undertaken to show that the same plant is never continuously fertilized by its own pollen, and that there are special provisions to favour the crossing of individuals. As his study of the British species advanced, he became so interested in the number, variety, and complexity of the contrivances he met with, that he extended his survey to the whole family, and the result is a work of which it is not too much to say that it has thrown more light upon the structure and functions of the floral organs of this immense and anomalous family of plants than had been shed by the labours of all previous botanical writers. It has, further, opened up entirely new fields of research, and discovered new and important principles that apply to the whole vegetable kingdom. This was followed by his paper on the two wellknown forms of the primrose and cowslip (Journal of the Linnean Society of London, vi. p. 77), popularly known as the pin-eyed and thrum-eyed; these forms he showed to be sexual and complementary; their diverse functions being to secure by their mutual action full fertilization, which he proved could only take place through insect agency. In this paper he established the existence of homomorphic, or legitimate, and heteromorphic, or illegitimate, unions among plants, and details some curious obser
vations in the structure of the pollen. The | Darwin's on the fertilization of plants; results of this, perhaps, more than any other some that appear to be commonplace at first of Mr. Darwin's papers, took botanists by surprise, the plants being so familiar, their two forms of flower so well known to every intelligent observer, and, his explanation so simple. For myself, I felt that my botanical knowledge of these homely plants had been but little deeper than Peter Bell's, to
A primrose by the river's brim
sight are really the most subtle, and, like many other apparent commonplaces, are what, somehow, never occur to commonplace minds; as, for instance, that plants with conspicuously-coloured flowers, or powerful odours, or honeyed secretions, are fertilized by insects;-all with inconspicuous flowers, and especially such as have pendulous anthers, or incoherent pollen, are fertilized by the wind; whence he infers that, before honey-feeding insects existed, the vegetation of our globe could not have Analogous observation on the demor- been ornamented with bright-coloured flowphism of flax flowers and their allies (Jour-ers, but consisted of such plants as pines, nal of the Linnean Society, vii. 69) formed oaks, grapes, nettles, &c. the subsequent paper, during which he The only other botanical paper of Mr. made the wonderful discovery that the com- Darwin's to which I can especially allude is mon flax, the pollen of one form of flower, that On the Habits and Movements of is absolutely impotent when applied to its Climbing Plants' (Journal of the Linnean own stigma, but invariably potent when ap- Society, vol. ix., p. 1), which is a most plied to the stigma of the other form of elaborate investigation into the structure, flowers; and yet both pollens and stigmas modification and functions of the various of the two kinds are utterly undistinguish-organs by which plants climb, twine and atable under the highest powers of the mi- tach themselves to foreign objects. In this croscope. His third investigation is a very he reviews every family in the vegetable long and laborious one (Journal of the Lin-kingdom, and every organ used by any nean Society, viii. 169) on the common plant for the above purpose. The result loosestrife (Lythrum salicaria), which he places the whole subject in a totally new showed to be trimorphic; this one species light before us. The guesses, crude obserhaving three kinds of flowers, all annually abundantly produced, and as different as if they belonged to different species; each flower has, further, three kinds of stamen, differing in form and function. We have in this plant, then, six kinds of pollen, of which five at least are essential to complete fertility, and three distinct forms of style.
To prove these various differences, and that the co-adaptation of all these stamens and pistils was essential to complete fertility, Mr. Darwin had to institute 18 sets of observations, each consisting of 12 experiments, 216 in all. Of the labour, care, and delicacy required to guard such experiments against the possibility of error, those alone can tell who know experimentally how difficult it is to hybridize a large flowered plant of simple form and structure. The result in this case, and in those of a number of allied plants experimented on at the same time, is what the author's sagacity predicted; the rationale of the whole was demonstrated, and he finally showed, not only how nature might operate in bringing these complicated modifications into harmonious operations, but how through insect agency she does do this, and why she does it too.
It is impossible ever to enumerate the many important generalizations that have flowed from these and other papers of Mr.
vations, and abortive experiments that had disfigured the writings of previous observers are swept away; organs, structures and functions, of which botanists had no previous knowledge, are revealed to them, and the whole investigation is made as clear as it is interesting and instructive. The value of these discoveries, which add whole chapters to the principles of botany, is not theoretical only; already the horticulturist and agriculturist have begun to ponder over them, and to recognize in the failure of certain crops the operation of laws that Mr. Darwin first laid down. What Faraday's discoveries are to telegraphy Mr. Darwin's will assuredly prove to rural economy in its widest sense and most extended application.
Another instance of successful experiment in Physiological Botany is Mr. Herbert Spencer's observations on the circulation of the sap and formation of wood in plants (Linnean Transactions, vol. xxv., p. 405). As is well known, the tissues of our herbs, shrubs and trees, from the tips of their roots to those of their petals and pistils, are permeated by tubular vessels. The functions of these have been hotly disputed, some physiologists affirming that they convey air, others fluids, others gases, and still others assigning to them far-fetched
uses of a wholly different nature. By a You may say that these cells have inherited series of admirably contrived and conduct- the potentiality to do so; but this is not all, ed experiments Mr. Spencer has not only for every plant thus produced in like manshown that these vessels are charged at cer- ner developes on its stalks and leaves tain seasons of the year with fluid, but that myriads of similar cells, endowed with the they are intimately connected with the for- same property of becoming such in new mation of wood. He further investigates plants; and so on, apparently interminably. the nature of the special tissues concerned Therefore the original cell that left the in this operation, and shows not merely grandparent, not only carried with it this how they may act, but to a great extent how so-called potentiality, but multiplied it and they do act. As this paper will, I believe, distributed it with undiminished power be especially alluded to by the President of through the other cells of the plant itself the Biological Section, I need dwell no fur-produced; and so on, for countless generther on it here than to quote it as an ex-ations. What is this potentiality, and how ample of what may be done by an acute ob- is this power to reproduce thus propagated, server and experimentalist, versed in phys- so that an organism can, by single cells, ics and chemistry, but, above all, thorough- multiply itself so rapidly, and, within very ly instructed in scientific methods. narrow limits, so surely and so interminably? Mr. Darwin's recent two volumes On Mr. Darwin suggests an explanation, by Animals and Plants under Domestication assuming that each cell or fragment of a are a catacomb of data, observations and plant (or animal) contains myriads of atoms experiments, such as assuredly no one but or gemmules, each of which gemmules he himself could produce. It is hard to say supposes to have been thrown off from the whether it is most remarkable for the num- separate cells of the mother plant, the gember and value of the new facts it discloses, mules having the power of multiplication or for its array of small, forgotten or over- and of circulating throughout the plant; looked observations, neglected by some their future development he supposes to naturalists and discarded by others, which, depend on their affinity for other partially under his mind and eye, prove to be of developed cells in due order of succession. first-rate scientific importance. An eminent Gemmules which do not become developed surgeon and physiologist (Mr. James Paget) may, according to his hypothesis, be transhas remarked to me, apropos of these vol-mitted through many succeeding generaumes, that they exemplify, in a most re- tions, thus enabling us to understand many markable manner, that power of utilizing remarkable cases of reversion or atavism. the waste materials of other scientific men's laboratories which is a very characteristic, feature of their author. As one of those pièces justificatives of his previous work, The Origin of Species,' which have been waited for so long and impatiently, these volumes will probably have more than their due influence; for the serried ranks of facts in support of his theories which they pre- As with other hypotheses based on the sent may well awe many a timid naturalist assumed existence of structures and eleinto bolting more obnoxious doctrines than ments that escape our senses, by reason of that of natural selection. It is in this work their minuteness or subtlety, this of Panthat Mr. Darwin expounds his new hypo- genesis will approve itself to some minds thesis of Pangenesis, which certainly corre- and not to others. To some these inconlates, and may prove to contain the ration-ceivably minute circulating gemmules will ale of all the phenomena of reproduction and of inheritance.
Thus, according to this hypothesis, not only
be as apparent to the mind's eye as the stars of which the milky way is composed; You are aware that every plant or ani- others will prefer embodying the idea in - mal commences its more or less independent such terms as potentiality," a term which life as a single cell, from which is developed conveys no definite impression whatever, an organism more or less similar to its pa- and they will like it none the less on this rents. One of the most striking examples account. Whatever be the scientific value I can think of is afforded by a species of be- of these gemmules, there is no question but gonia, the stalks, leaves, and other parts of that to Mr. Darwin's enunciation of the which are superficially studded with loosely- doetrine of Pangenesis we owe it that we attached cells. Any one of those cells, if have the clearest and most systematic réreferred to favourable conditions, will pro-sumé of the many wonderful phenomena of duce a perfect plant, similar to its parent. reproduction and inheritance that has
appeared; and against the guarded enter- in from the Continent, and Agassiz, in one tainment of the hypothesis, or speculation of the addresses which he issued to his colif you will, as a means of correlating these laborateurs on their late voyage to the Amaphenomena, nothing can be urged as in the zon, directs their attention to this theory as present state of science. The President of a primary object of the expedition they the Linnean Society, a proverbially cautious were then undertaking. I need only add, naturalist, thus well expresses his own that of the many eminent naturalists who ideas of Pangenesis: "If," he says, we take into consideration how familiar mathematical signs and symbols make us with numbers and combinations, the actual realization of which is beyond all human capacity; how inconceivably minute must be those emanations which most powerfully affect our sense of smell, and our constitutions; and if, discarding all preventions, we follow Mr. Darwin step by step in applying his suppositions to the facts set before us, we must, I think, admit that they may explain some, and are incompatible with others; and it appears to me that Pangenesis will be admitted by many as a provisional hypothesis, to be further tested, and to be discarded only when a more plausible one shall be brought forward."
have accepted it, not one has been known to abandon it; that it gains adherents steadily, and that it is par excellence an avowed favourite with the rising schools of naturalists; - perhaps, indeed, too much so, for the young are apt to accept such theories as articles of faith, and the creed of the student is also too likely to become the shibboleth of the future professor. The scientific writers who have publicly rejected the theories of continuous revolution or of natural selection, or of both, take their stand on physical grounds, or metaphysical, or both. Of those who rely on the metaphysical, their arguments are usually strongly imbued with prejudice, and even odium, and, as such, are beyond the pale of scientific criticism. Having myself been a student of moral philosophy in a northern University, I entered on my scientific career full of hopes that metaphysics would prove a useful Mentor, if not quite a science. I soon, however, found that it availed me nothing, and I long ago arrived at the conclusion, so well put by Agassiz, where he says, "We trust that the time is not distant when it will be universally understood that the battle of the evidences will have to be fought on the field of physical science, and not on that of the metaphysical." (Agassiz on the Contemplation of God, in the Kosmos, Christian Examiner, 4th series, vol. xv., p. 2.) Many of the metaphysicians' objections have been controverted by that champion of natural selection, Mr. Darwin's true knight, Alfred Wallace, in his papers on Protection (Westminster Review) and Creation of Law,' &c. (Journal of Science, October, Since the Origin' appeared, ten years 1867,) in which the doctrines of "continual ago, it has passed through four English edi- interference," and the "theories of beauty," tions, two American, two German, two kindred subjects, are discussed with admiFrench, several Russian, a Dutch, and an rable sagacity, knowledge and skill. But Italian; while of the work on Variation, of Mr. Wallace and his many contributions which left the publisher's house not seven to philosophical biology it is not easy to months ago, two English, a German, Rus- speak without enthusiasm; for putting aside sian, American, and Italian edition are al- their great merits, he, throughout his writready in circulation. So far from natural ings, with a modesty as rare as I believe it selection being a thing of the past, it is an to be unconscious, forgets his own unquesaccepted doctrine with every philosophical tioned claims to the honour of having origi naturalist, including, it will always be un-nated, independently of Mr. Darwin, the derstood, a considerable proportion who theories he so ably defends. are not prepared to admit that it accounts for all Mr. Darwin assigns to it. Reviews 'The Origin of Species' are still pouring
Ten years have elapsed since the publication of The Origin of Species by Natural Selection, and it is hence not too early now to ask what progress that bold theory has made in scientific estimation. The most widely-circulated of all the journals that give science a prominent place on their title-pages, the Athenæum, has very recently told it to every country where the English language is read, that Mr. Darwin's theory is a thing of the past: that natural selection is rapidly declining in scientific favour; and that, as regards the above two volumes on the variations of animals and plants under domestication, they "contain nothing more in support of origin by selection than a more detailed re-asseveration of his guesses founded on the so-called variations of pigeons." Let us examine for ourselves into the truth of these inconsiderate state
On the score of geology, the objectors rely chiefly on the assumed perfection of the geological record; and since almost all