Page:Science vol. 5.djvu/513

 SCIENCE.

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To studeota o[ natural science no term is more familiar than ' morphologj',' and no doctrine more commonly accepted and understood. Pre-eminently reasonable and natural, the morphol(^y of plants in particular appeals to the simplest understanding. Everj- schoolboy who has prepared bis perfunctory herbarium, or accomplished his stint in plan^analJ'BiB. knoTvs something of the meaDing of a flower, can tell something of its natural history, — how that bract and sepal and petal, stamen and carpel, are but so many modifications of an ideal leaf, so many varied expressions of a single thought, LUiewise the facts to be cited in proof of such assertions are familiar to every-day experience. Who has not gathered pond-lilies, and noted how, by the steps of im- perceptible transition, Nature passes on (Vom green sepal lo perfected anther? ' Double ' flowers of all sorts grow in country gardens, and in springtime the woodland oK'era anem- ones which are both 'double' and green. Even prolification is widely known in fact, if not in name.

To all these morphological facts, strange and curious as they certainly are, no one ever at- tempts to apply any other than the accepted explanation : no other is conceivable, none other is needed. And yet much of the ease with which such explanations are received must be considered due to the habits of thought now prevalent in the world, to the veiy atmos- phere in which to-day men are called to think, to judge. In all the world of thought, ideas of transition are so rife, that unity or com- munity of origin, even of objects most dis- similar, excites small surprise : it is the natural supposition. A diflferent atmosphere. different habits of thought among men, would change completely the simplicity of many a modern page. It is, then, not surprising that a century ago morphologj, as we know it, had not so much as found a name; that, with the same facts before them, the best minds in Eu- roi>e were struggling to the perception of this simple theory, which the schoolboy may now appreciate and understand. The first percep- tion of natural truth, like the opening-up of unknown lands, is a discovery, dim enough when seen in prospect, however easy when once accomplished. Linked with the botanical

��discovery here to be considered are three most brilliant names, two the brightest of their century, — LinnS, Wolff, Goethe : not that all contributed equally to the establishment of the truth, but that to each the problem came, and for it each found answer. What answer to the floral problem each of these great men could give, it is onr purpose here briefly to set forth. considering first the labors of Linn^' and Wolff, later those of Goethe.

Linn6, the first in order of time, may he said to have discovered the problem. Passing his hfe in the study of flowers, the question ' What is a flower ? ' must have come to the great botanist again and again, pressing him by its very omnipresence almost to his annoj-ance. But to Linn^. fortune -favored, the whole natu- ral world lay like an undiscovered country. — a world too wide for the comprehension of any one mind, however active or versatile. It has been the marvel of all men since bis time. that Linn^ did so much, that his instinets were so true, that to ao many questions he gave answers which are the end of controversy. But as regards the morphological problem, the great naturalist seems never to have arrived at a definite conviction. Everj' thing he says on the subject is more or less obscure. Here, for once, he seems to have reasoned a priori. and fancy strangely supplements and distorts the facts discussed. The coincidence of num- ber nffoi-ded by the successive layers in the make-up of the stem and the successive circles of organs in the composition of the flower struck him as aflbrding a plausible explanation of the origin of the latter structure. Here are four layers, — the outer bark, the inner bark, the wood, and the pith. The outer bark is often on growing stems green, passing to all appear- ances imperceptibly into the green covering of the calyx ; from the inner bark, white and delicate, come the delicate petals of the corolla : while from the cellular xylem and pith of the stem arise the circles of stamens and carpels respectively ; and in the young flower-buil are not the organs last named simply mosses of cellular tissue hartUy to be distinguished from forming wood and pith? A more careful anatomy would liave revealed the mistake ; for, as Goethe points out in this connection, ■■ it is the inner bark alone which possesses all power of life and growth ; " the other parts of the stem having in the main taken on definite character, and been relegated to inactivity. If we may regard the ' pith ' at the end of the growing axis as primary meristem, then so far so good ; and the fancied relationship is not williout its grain of truth.

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