Spine (plant)

“ How curious are the leafless but leaf-like dilatations of the stem—these flat oval plates of parenchyma, studded with clusters of woody and most acute spines!—Every one of these expansions is an expression of time, as they are of course successive, though several may be formed in a single season; and not only so, but the tufts of spines, which grow at the points of intersection of crossing lines, in a network pattern, are all successive, appearing in turn as the expanded joint of the stem grows out. ”

“ It is a well-known physiological fact in botany, that many plants which are naturally spinous, when cultivated in gardens or rich soil, become unarmed. The production of spines seems to arise from an imperfect development of the growing point of a plant ”

“ It is well known that, under ordinary circumstances, these plants do not flower except at long intervals of time.
Presence of flowers on spines.—That the spine, as a contracted branch, should occasionally produce flowers is not to be wondered at, though the occurrence is by no means common. M. Baillon showed at a meeting of the Botanical Society of France ('Bulletin,' vol. v, 1858, p. 316) a branched spine of Gleditschia bearing a flower at the end of each of the sub divisions. This was, therefore, strictly analogous with those cases in which the peduncle is normally spiney. ”

“ In some, the spines are erect and hair-like, giving the plant the appearance of tiny sea-urchins; another group has the principal spines hooked at the tip, and the points in these so sharp that if the hand comes in contact with them they hook into it and stick like fish-hooks. The purpose of these hooked spines seems doubtful; certainly, they cannot serve as any protection to the plant itself, as they are so strong that the plant must be torn up by the roots before the hooks will give way. ”

“ Spines generally occur along the whole margin of the leaf, though in a few forms, especially in cultivated varieties, they may be present only at the tip or may be wanting entirely. The marginal spines usually curve forward and vary in size from small, hardly perceptible forms, to large sharp conical structures. At times they are set very close together; again they may be several centimeters apart. Those on the midrib most often curve backwards and may vary the same as the marginal spines. Generally the spines are green in color, though in some species they are pale-green, red, black or white. ”

“ Spines three-sided prismatic, straight, or in the basal half slightly curved, verticillate; each spine with six to eight three-branched regular verticils, tapering gradually towards the distal end. All branches of each spine lie parallel in three equidistant meridian planes, and are connected by delicate parallel threads, perpendicular to the branches. Therefore the skeleton consists of four pine-shaped trees and twelve delicate triangular wings with rectangular meshes. ”

“ The scales of the underside of the body are of the same form as those of the back, and are furnished with similar but smaller and less produced spines. The back of the neck of the two specimens I have seen is furnished with a large rounded protuberance like a cherry, covered with large granular spinous scales, and armed on each side with a large conical spine; but I do not know if this is common to the species or merely accidental in these individuals ”

“ A neck-swing, and lying down in the day, should be occasionally used to prevent or remove any curvature of the spine. The rest as in Species 13 and 15 of this genus.
18. Spina protuberans. Protuberant spine. One of the bones of the spine swells, and rises above the rest. This is not an uncommon disease, and belongs to the innutrition of the bones, as the bone must become soft before it swells; which softness is owing to defect of the secretion of phosphorated calcareous earth. The swelling of the bone compresses a part of the brain, called the spinal marrow, within the cavity of the back-bones ”

“ The fibres descending from the developing buds on the stem, and passing between the plates of cellular tissue, which constitute the medullary rays, and the cells of which have a horizontal direction, are but the basis of the vegetable fabric. The stem of an exogenous plant has been compared to a piece of linen, of which the weft is composed of cellular tissue, and the warp of fibrous and vascular tissue—crossing each other. ”

“ Spines equal, straight, three-sided prismatic, thorny, connected by three convex bows, the meeting branches of lateral spines arising in one pair from the middle part of each spine. Therefore the skeleton exhibits three large ovate meshes only. ”

“ When the leaves of a plant are spinose the spines are disposed on the parts usually attacked; and thus we understand why the enormous floating leaves of Victoria regia should have on their under surface long, pointed spines which, especially at the upturned margin, attain a length of several inches; it is from water animals—water snails—that danger threatens them. ”

“ It is not invariable in a long series of female examples; occasionally one is found with four spines on one of these genual joints, in others there is occasionally but one spine and sometimes (but rarely) none; perhaps in this case broken off? I am inclined to attach some importance as a specific character to the number, presence, or absence of these spines on the outer side of the genual joint of the third pair of legs ”

“ The spine is, in fact, a long narrow causeway, made of large stones, set like the vertebræ of some huge animal. They form a ridge sloping off in an angle at each side, which is continued downwards with an arrangement of smaller stones, suggestive of ribs. ”

“ The bark or cellular tissue of these leaves is penetrated by the fibres of the wood in the shape of reins, veinlets and capillaries, which communicate directly with the fibres of the stem and roots, and thus act as conduits of the sap from one extremity of the plant to the other. In this manner the sap brought from all the other parts of the plant is conducted to all parts of the leaf by these veins, veinlets and capillaries, to be thoroughly spread out and aerated in the leaves. ”

“ Passing towards the margin are other rows conveying the impression of a beautiful indented reticulated tissue. Many of the spines present no structure, while others exhibit a series of concentric rings of successive growth, which strongly remind one of the medullary rays of plants. When a vertical section of a spine is submitted to examination, it is seen to be composed of cones placed one above the other, the outer margin of each cone being formed by the series of pillars. ”

“ Phyllody in accessory organs.—In addition to the ordinary organs of the plant, what are termed the accessory organs, such as hairs, spines, &c., sometimes become foliaceous. It is not to be wondered at that spines, when they represent the framework of a leaf, become sometimes clothed with cellular tissue, and thus become indeed true leaves. This happens occasionally in Berberis; a similar thing occurs in the stipules of some Leguminosæ ”

“ Comparing this form with the more spinose species of Tuzoia, we note first the extraordinary extension of the dorsal line into long, upturned spines such as we find in some living Crustacea. Assuming that the longer spines occur on the rear margin and that the outer edge extends only to the keel, we note the very long spine in the usual position between the dorsal extension and the keel. If this is only the inner part of the test one or more marginal spines should occur beyond the keel. At least five spines edge the anterior margin exclusive of the dorsal extension. ”

“ The young plant has a circle of leaves, about six in number, surrounding a bud which is the growing point of the stem, and in many conifers persists as long as the stem grows (Fig. 75, K, b) . A cross-section of the young stem shows about six separate fibro-vascular bundles arranged in a circle (S, fb.) . The root shows a central fibro-vascular cylinder surrounded by a dark-colored ground tissue. Growing from its surface are numerous root hairs (Fig. 75, M) . ”

“ Spines slightly curved, three-sided prismatic, with two to three verticils of short curved branches. The vertical apical spine is about twice as long as the three basal spines, and connected with them by an irregular loose framework. ”

“ It is an interesting fact that the spine is the central and fundamental structure of all the higher organisms on this earth. In the course of the evolution of life on this planet there developed from the very simplest forms of animal organisms two different higher forms of life- on the one hand the vertebrate animals, possessing an internal skeleton, and on the other hand the insects, clams, crustaceans and other creatures that have their skeletons on the outside, as one may say, in the form of shells. ”

“ The vertebræ, or joints of the spine, are excavated at each end in a conical cavity; the hollow thus formed between every joint and its neighbour is filled with a jelly-like substance, which is continuous through the whole spine, by means of a hole pierced through the centre of each vertebra. There is no true spinal marrow. ”

“ Both stem and leaves are covered with sharp spines, which pierced our clothes as we forced our way through the tangled growth, and made the legs and hands of the pioneers scarlet from the inflammation of myriads of punctures. ”

“ Upon the edges of the flat border are sharp-pointed, colorless, spine-like processes, situated at equal distances around the entire periphery except at the anterior end. Each spine is thick at the base and tapers to a full point which is curved upward—i. ”

“ The Fibres or Nerves dispersed through the Leaf, are only the Ramifications of the Branch’s Wood, or Lignous Body. The Parenchyma of the Leaf which lies betwixt the Nerves, and as in Gentlewomens Needle-works, fills all up, is nothing else but the continuations of the Cortical Body, or inner part of the Barque from the Branch into it self, as in most Plants with a fat Leaf, may easily be seen. ”

“ In the same region a strange plant was obtained for the first time, but then without flowers or fruit, and which, to the casual observer, appeared as curious as it is puzzling to the scientific botanist; single spiny sticks or stems having a soft and brittle wood, and a great deal of pith in the centre, one or more from the same root, but always without branches, 8 to 10 feet high, not more than half an inch thick, frequently overtopping the brush among which they were found, only towards the top with a few bunches of already yellow leaves. ”

“ Just as the muscular arm has been the determining factor in the structure of the Ophiuroidea, so the movable spine has been {506}the leading factor in the evolution of Echinoidea. The spines have cup-shaped basal ends, which are inserted on special projections of the plates of the skeleton called tubercles. The tubercle is much larger than the cup, and hence the spine has a great range of possible motion. ”

“ When we speak of one thing as being developed out of another, we imply that the parts next to the germ are the first to appear, and the most constant. In the evolution of a tree out of a seed, there come at the outset the stem and the radicle; afterwards the branches and divergent roots; and still later the branchlets and rootlets; the remotest parts being the latest and most inconstant. If, then, a limb is developed out of a “diverging appendage” of the hæmal arch, the earliest and most constant bones should be the humerus and femur ”

“ We have the stem acquiring the characters of the leaf, and the leaf those of the stem. Thus we have seen leaves, leaf-buds, branches, and flower-buds springing from leaves or leaf-organs; [555] see pp. 174, 177, 445, &c. The structure that we [Pg 479] are apt to associate exclusively with one is found to pertain to the other. The arrangement of the vascular cords in the leaf-organ finds its counterpart in the axis, generally, it is true, modified to suit altered circumstances or diverse purposes. In some cases the disposition is absolutely indistinguishable in the two organs. ”

“ I was able to distinguish that the two lower pair of spines on the ventral surface, are seated a little way one below and within the other, as in S. vulgare. The abdominal spines altogether form quite a brush, and there are certainly several more than in S. vulgare, and those on the two sides are much longer.
Antennæ.—The disc is hoof-like, with the upper surface forming a straight line with the upper edge of the basal segment; the apex is pointed and clothed with some fine down; there is a single spine pointing backwards, which rises from the lower flat surface. ”

“ A. I thank you, Isabel. Now, what is this spine, of which there is so much "complaint" now-a-days?
I. I will answer you from Paley: "The spine, or backbone, is a chain of joints of very wonderful construction. It was to be firm, yet flexible; firm, to support the erect position of the body; flexible, to allow of the bending of the the trunk in all degrees of curvature. It was further, also, to become a pipe or conduit for the safe conveyance from the brain of the most important fluid of the animal frame, that, namely, upon which all voluntary motion depends, the spinal marrow ”

“ The first of the three dorsal spines is very strong, roughened in front like a file, and hollowed out behind to receive the second much smaller spine, which, besides, has a projection in front, at its base, fitting into a notch of the first. Thus these two spines can only be raised or depressed simultaneously, in such a manner that the first cannot be forced down unless the second has been previously depressed. ”