vegetationis. A leaf can never be formed at a later period from the developed axis. It is a necessary consequence of the manner in which the leaf originates, that an absolute dividing line cannot. be drawn between leaf and axis; for the subsequent position of the leaves upon the organism affords no standard of appreciation, especially as most of them do not mark the basis of the leaf, which loses itself in the axis. Earlier, before the extension of the axis begins, the rudiments of the leaves are always closely pressed together, so that they appear as a peripherical development of the axis itself, occupying the whole upper surface, and dividing it into clearly defined planes, which may be recognised even in the developed state, in those plants whose foliaceous pulvini are distinctly marked, as e. g. in many Ferns, most acerose plants, in Cacti, and particularly in Nymphaea and Victoria where the pulvini may be distinguished even in the interior of the axis. The primitive vascular system of the axis enters directly into the leaves, and ramifies there; while the woody layers of the stem, which are found later, have no connexion with the leaves. With branches the case is totally different. In their origin and development they always succeed the leaves; and even at a much later period, when the leaves have been long cast off, shoots may originate in places where, at an earlier period, no trace of a rameal rudiment, or of an eye, was to be found. If we now consider the axillary shoots,-i. c. those branches whose position is predetermined by the situation of the leaves,-at an early period we shall find their rudiments, even though they develop very late or not at all, in the form of a circular and slightly prominent gibbosity, which may be compared with the apex of the axis; or rather, it is an accessory punctum vegetationis forming near the apex. The circumstance of the epidermis of the axillary shoot's being a continuation of that of the stem, is explained by the early date. at which it originates; for this takes place at a time when the surface of the axis has not yet lost its flexibility. The eye is shown to be an independent centre of vegetation by its subsequent internal and external conformation; for it not only develops leaves upon its surface, and this too with an independent commencement of its phyllotaxis, but even in its interior the first system of vascular fibres seems to be formed independently of that of the main axis; as originally it lies upon it, and afterwards becomes intimately blended with it by later layers of tissue. Notwithstanding the intimacy with which later formations of woody tissue unite branch and stem, still, according to Unger's investigations, no immediate influence is exerted by the branch upon the conformation of the stem, since the stem owes none of its essential parts to the branches.* This independence of the branches is shown still more decisively in adventitious shoots, whose posi* Unger: Ueber den Bau des Dicotyledonen-Stammes (1840), p. 65, et 66. tion is not predetermined by the leaves. Originating at a later period, they take their rise not from the surface but from the cam bium layer, the internal tissue which preserves the faculty of producing new growths. Hence if they would come to the light of day they must break through the bark. Their origin has been particularly described by Trécul.* W. Hofmeister, however, as I have already remarked, succeeded in tracing it in Equisetum back to the first cell, a cell in the interior of the stem. As is the case with axillary buds, such adventitious buds sometimes remain undeveloped for a long time (ten years and more) without losing their vital activity; a fact to which attention has lately been called by C. Schimper,† in a report on exostoses. When this is the case they not unfrequently develop into spherical or conical wood-kernels, which continue to exist without any connexion with the ligneous body of the maternal stem; this is especially the case in Beeches and Poplars. The individual nature of the shoot is confirmed not only by the mode, but by the place, of its origin. While the organs of the individual organism,-the leaves of the plant,-occupy a posi tion determined with geometrical accuracy, shoots on the contrary can arise out of almost any part of the plant, wherever indeed any cambium exists; and they may be even enticed by art out of places where they do not usually appear. There are shoots from the stem, the root and the leaves. In herbaceous stems they appear in situations determined by the leaves (in the axils of the leaves), while they may be found anywhere on old woody stems as adventitious buds, or on any part of the lig nified roots of most dicotyledonous woody growths, and even on some monocotyledonous ones, as in umbraculiferæ. Shoots appear less frequently on the roots of herbaceous plants. Shootformation from leaves has often been discussed and described in regard to many plants, especially Bryophyllum, Cardamine pratensis, Drosera, Malaxis paludosa, etc. A fine example of this is shown by a Chelidonium majus var. laciniatum reared by Bernhardi in the Botanical Garden at Erfurt, from whose leaves Trécul Recherches sur l'orig. des bourg. adv. Ann. des sc. nat., viii, (1847) p. 268. In Sept., 1852, in the Versammlung der Naturforscher in Wiesbaden. Rarely scattered shoots appear on the herbaceous stem, and especially on the first internode under the cotyledons, as Röper (Enum. Euphorb. 1824) first showed in Eu phorbia, and Bernhardi in the germ of Linaria. A specimen of Begonia manicata, dipetala cultivated in our [Berlin] Botanical Garden, which is probably the same species as the B. phyllomaniaca of Martius, presents the case of a plant which produces a multitude of shootlets in the whole leaf-region; they arise from the sappy stem which is not yet hardened, soon after the fall of the leaves. According to Rheede, Corpypha umbraculifera sends forth root-shoots when the stem dies off after the fruit has ripened. I have often observed them in Linaria vulgaris, Helichrysum arenarium, Rumex Acetosella, Ajuga Genevensis, Jurinea Pollichii, Nasturtium sylvestre et Pyrenaicum. According to Wydler, they often appear in Viola sylvatica. floral bractlets arose, partly unifloral, partly multifloral, without any preceding leaves.* Shoots may be allured by the gardener out of most leaves which do not wither too soon.† Finally, the little budlets in whose bosom the germ of the new plant is formed and developed, and which we call seeds, are a kind of shoots, which in most cases owe their origin to leaves, (carpels) out of which they spring (on the margins, which unite to form the placenta) or more rarely, out of their whole inner surface. (To be concluded in our next number.) ART. XVIII.-On Different Centers of Primitive Civilization; by THOMAS H. MCLEOD. We have already called attention in a previous number of the Journal of Science‡ to the radical difference of the Indian, Grecian and Roman Systems of Numerical Notation. We would again refer to those several Systems, and in addition, to the Egyptian, Mexican and Chinese, in reference to different centers of primitive civilization. It will be remembered that the Indian System commences with a 0 (zero), and is made up of principal and subordinate measures, and has its origin probably in land or lineal measuring; that the Grecian System is a system of principal and subordinate measures also, but has no 0 (zero), its first figure being a unit, making use of mere characters to express its large measures, and has its origin in the contemplation of individual objects; that the Roman System also has no 0 (zero), its first character being a unit, and is rather a system of fives than of tens, introducing a new character (V) for that number, one for ten (X), which may be regarded as a double V, one for fifty (L), one for one hundred (C), one for five hundred (D), and one for one thousand (M), expressing the intermediate numbers by repetitions and combinations. The Egyptian System commences with a unit which it represents by a single downward stroke, adding an additional stroke for each successive number to ten which it denotes by a triangular figure (A); this figure is repeated for each successive ten to one hundred. The scheme will be seen by the following representation: I, II, III, IIII, IIIII, III, III, III, шш, ^, ^^, ^^^, ^^^^, &c. *I may add to the examples I have given of shoot-formation taking place out of the leaves, one which I observed in June, 1853, in Levisticum officinale. I found, in fact, in several species of this Umbellifera, one or more, frequently two, shoots in the points of division of the leaves, which after producing a few weak leaves bore a small umbel. (Later note.) ciosa. Kirschleger (Flora 1844, No. 2) notices a fine example of this in Gloxinia spe Journal of Science for January, 1855, Art. vii. SECOND SERIES, Vol. XX, No. 59.-Sept., 1855. 26 "The Aztecs expressed the digit one by a small circle, thus, 0. Months were expressed by a peculiar symbolic figure for each, taken from natural or artificial objects. Duplications and combinations of the circle were made adjacent to the symbol so that the day of the month was exactly denoted. These were also the formulas for other transactions."* The Chinese System con. sists of thirteen distinct characters and is a system of juxtapositions. The unit, which is the first figure in the system placed adjacent to a certain character denotes one hundred, two units placed with this character denotes two hundred, &c. From this statement it is manifest first, that, the Indian, Chinese, Egyptian, Mexican, and probably the first system of the Greeks are radically different and primitive; secondly, that, the Roman System and the second system of the Greeks, which is similar to the Roman, is a simplification of, and derived from, the Egyptian; and thirdly, that these several systems originated in the very earliest periods of the human race before the several stocks of these nations had made any advancement in common, in civilization, and after they had separated from each other, for they could not have advanced far in the cultivation of the arts and sciences without a method of numerical notation,-not even from the savage state; for the savages of North America were beginning to form a rude system, when they were first known to the Europeans, so that it may be justly inferred that the several nations with whom the several systems of notation above alluded to were formed, separated before they had advanced in civilization beyond the North American Indians. Consequently there must have been several points on the earth distant from each other, where the mental energies of man were developed and primitive civilization began. These points, as evinced by the above facts, were probably, the East Indies, Egypt, possibly Greece, Mexico and Central America, and China. ART. XIX. Additional Note on Arachis hypogaa; by GEORGE BENTHAM, Esq.t In the year 1838 a short paper of mine was read before the Linnæan Society on the structure and affinities of the Arachis, in which I pointed out the curiously imperfect achlamydeous female flowers from which the fruits are produced, whilst the apparently perfect hermaphrodite flowers are, generally speaking, if not always, barren, and I showed a closely similar structure and fructification in Stylosanthes, next to which I proposed to place Arachis among Hedysarea. This paper was published in the eighteenth volume of the "Linnæan Transactions," a work *Extract from a private letter from Hon. H. R. Schoolcraft. which is unfortunately far too expensive and bulky to have any circulation among foreign botanists. The conclusions I had come to became known to them only by abstracts contained in botanical journals or other compilations, unaccompanied by the observations from whence they had been deduced; and my proposal for associating Arachis with Hedysarea has been more than once treated as absurd, without however any facts or arguments being brought forward in opposition. Recently again a writer in "Silliman's American Journal," Mr. Hugh M. Neisler, whose article is reproduced in the last number of "Taylor's Annals of Natural History," adduces some observations of his own in support of a denial of the existence of the two kinds of flowers in Arachis, although he also had not seen my paper, the details of which would probably have led him to perceive his mistake. At the time I wrote it I had only had dried specimens to examine, but these were numerous and good, belonging to several species of Arachis, and to about twenty species or marked varieties of Stylosanthes. I have since then repeatedly examined dried specimens of both these genera, as well as of Chapmannia, and have observed Arachis hypogaa in a living state, especially in the summer of 1853, when I had the opportunity, in the Botanic Garden at Leipzig, of rooting up and carefully examining several plants of that species, bearing a profusion of flowers of both kinds, in various stages of development. These flowers always appear several together, in short, close spikes, in the axillæ of the leaves. In the upper axillæ, the barren but apparently perfect flowers are the most numerous; but even these are generally accompanied by one or more of the minute fertile ones, and the latter, which are always without calyx or corolla, become more numerous in the lower axillæ. The withered perfect flowers remain long sticking about the spike, and may sometimes be found apparently adhering to (but not connected with) the point of the fertilized ovary of the female flower, and borne along with it as its stipes lengthens, as mentioned by Mr. Neisler; but I always find within the tube of these withered flowers their own dried up, barren ovary, with its unfertilized ovules, and if Mr. Neisler will compare these barren ovaries with those of the female flowers before the stipes has lengthened above a line or two, he will find the latter very different in shape, smaller in size, with a small sessile stigmate, wholly incompatible with the supposition of its ever having borne the long filiform style of the barren ones. The presence of imperfect flowers, deprived of corolla and even of calyx, but more prone to form their seed than the more showy and perfect ones on the same plant, is a phenomenon of not unfrequent occurrence among Leguminosa, especially in several genera of Phaseoleæ and Hedysarea, and has also been observed in other Natural Orders, such as Cistineæ, Violacea, Malpighiacea, etc. |
