Alfred William Bennett

“ The rapid rotatory motion of the zoospores of the lower Algæ is absolutely undistinguishable from that of certain undoubted lowly organized forms of animal life. It is very difficult to distinguish between the movement of a shoot of a climber performing its circles in the air in search of a support, and that of the tentacula of a coral-polyp in search of food. The mode in which the Venus's Fly-trap seizes and encages its prey is very like that adopted by a sea-anemone. ”

“ THAT there are no "hard and fast lines" in Nature is a truth which is more and more forcing itself upon the minds of men of science. The older naturalists delighted to circumscribe their own special domains within sharply-marked boundaries, which no trespassers were allowed to pass. We have long given up the attempt thus accurately to map out the kingdom of Nature. ”

“ In describing these curious bodies, of the connection of which with the vegetable kingdom there is no room for doubt, one is irresistibly reminded of these lowly forms of animal life known as Amœba and Gromia, consisting apparently of shapeless masses of protoplasm possessing indeed far more restricted powers of locomotion than the zoospores and spermatozoa, their faculties in this respect being confined to the protrusion and retractation of arms or pseudopodia, by means of which a slow movement is effected. ”

“ It should rather be said that plants acquire and display this power only when it is of some advantage to them, but that this is of comparatively rare occurrence, as they are affixed to the ground, and food is brought to them by the wind and rain. We see how high in the scale of organization a plant may rise, when we look at one of the more perfect tendril-bearers. It first places its tendrils ready for action, as a polypus places its tentacula. If the tendril be displaced, it is acted on by the force of gravity, and rights itself. It is acted on ”

“ The sensitiveness of the leaves of plants is but an excessive development of the phenomenon known as the Sleep of Plants. In the case of the Sensitive-plant the position assumed by the leaf and leaflets in the night is the same as that which they assume when disturbed in the daytime; and with many other plants, such as the clover and the Robinia or "acacia" tree, the change in the position of the leaflets, morning and evening, is a familiar fact. The Sleep of Plants extends also to the flowers, many plants opening their flowers only at particular times of the day. ”

“ The end of the growing shoot has, in fact, the property of revolving in a large circle, round the support, always, with the same species, in the. same direction, either with the sun or opposed to the sun. The rate of revolution varies with different plants, and with the same plant at different periods of its growth; it is much quicker in warmer than in cooler weather. ”

“ If the possession of consciousness and of a voluntary control over the movements of the body belongs to the animal kingdom even to its lowest forms, it is difficult to frame any cogent reason for denying these faculties to the vegetable organisms which we have been considering. ”

“ In particular, the selective power of plants, in absorbing from the soil a larger portion of those ingredients which are required for the formation, or healthy life, of their tissues, is an absolutely unexplained phenomenon. ”

“ So great is the uncertainty as to the actual boundary-line, that large groups of lowly organisms, such as those known as Diatoms and Desmidiæ, have been regarded by experienced authorities as belonging to each kingdom ”

“ Darwin has seen a tendril keep its point, in one instance, for twenty hours, and, in another instance, for thirty-six hours, in a minute hole, and then withdraw it. After the record of this fact on such unexceptional evidence, we are the more prepared to credit the statement of Mr. Anderson-Henry, that a climber will, in running up a wall, carefully avoid contact with another climber which it dislikes ”

“ With the hop, Darwin found it to vary from two and a half hours to nine hours. The object of the climbing power of plants is no doubt to reach the light, and to expose a large surface of leaves to its action and to that of the free air; but the mode by which this power of motion is gained is by no means clear. The late eminent physiologist Mohl supposed that it was caused by a dull kind of irritability in the stem, which caused it to bend toward the support when in contact with it. Mr. Darwin has, however, carefully tested this theory experimentally, and always with negative results. ”

“ With others this is not so easy; and it is but reasoning in a circle to say that, because the organisms which manifest them belong to the vegetable kingdom, therefore the phenomena cannot be the result of a sentient force acting upon, and independent of, matter. Darwin has described how certain movements of the tendrils of climbing plants would be termed instinctive if they were observed in animals. ”

“ The Virginian creeper has another mode of attaching itself to a wall or other solid support, by the formation, at the extremities of the branches of the tendril, of little disks or cushions, very similar to the disks on the foot of the house-fly, by which it is enabled to attach itself to our windows, and to walk along the ceiling. ”

“ The same purpose as that served by a climbing stem is answered in other plants, as the vine, Virginian creeper, and passion-flower, by tendrils; and the phenomena of spontaneous motion in tendrils are, if possible, still more curious. Some tendrils display the same power of rotatory motion possessed by the extremities of the shoots of climbing plants; others do not revolve, but are sensitive, bending to the touch. The curling movement, consequent on a single touch, continues to increase for a considerable time, then ceases ”

“ We may conclude our account of climbing plants with the following remarks by Mr. Darwin: "It has often been vaguely asserted that plants are distinguished from animals by not having the power of movement. ”

“ Her varied productions are connected with one another by innumerable links and cross-links; and our systems of classification, even the most "natural," are but an imperfect human contrivance for bringing together those forms which present the most evident marks of resemblance or affinity. ”

“ There are animals, so regarded by the best naturalists, and possessing other characters which compel us to refer them to this class, whose power of motion is confined to the "contractility" common to all protoplasmic substance, and which are absolutely devoid of a nervous system; and there are plants, unquestionable plants, which possess powers of spontaneous motion strictly comparable to those exhibited by the lower animals. ”

“ When the inside of the blade of the leaf, or the fine bristles which grow on its surface, are touched by any foreign substance, the hinge suddenly closes, and if the intruding substance be a fly or other small object, it is immediately imprisoned as represented in the figure, the teeth on the margin of the leaf closing firmly upon one another like a steel trap, the sides of the trap then flatten down and press firmly upon the victim, and it now requires a very considerable force to open the trap. If nothing is caught, the trap presently reopens of itself, and is ready for another attempt. ”

“ It is also very curious that, with some exceedingly sensitive plants, the falling of drops of rain on the tendril will produce no effect whatever. The mode in which a tendril of a Bignonia catches hold of a support is thus described by Darwin: "The main petiole is sensitive to contact with any object; even a small loop of thread after two days caused one to bend upward. The whole tendrils are likewise sensitive to contact. Hence, when a shoot grows through branched twigs, its revolving movement soon brings the tendril into contact with some twig, and then all three ”

“ The mode of reproduction of the Algæ, the lowest class of the vegetable kingdom, to which the sea-weeds and the fresh-water confervæ belong, is often obscure, and in some cases different distinct processes exist in the same species. ”

“ During several days the tendrils or internodes, or both, spontaneously revolve with a steady motion. The tendril strikes some object, and quickly curls round, and firmly grasps it. In the course of some hours it contracts into a spire, dragging up the stem, and forming an excellent spring. ”

“ This phenomenon appears, however, to be but a form of the property possessed by all protoplasm, of constant motion in some form or other. The circulation of the protoplasmic mucous fluid within the cells of plants is one of the most beautiful phenomena of vegetable life revealed by the microscope, and one of which the explanations at present offered appear quite inadequate. A favorite object for exhibiting this circulation or rotation is formed by the jointed hairs which cover the stamens of the Virginian spider-wort (Tradescantia Virginica) . ”

“ Those zoospores which are furnished with cilia at one extremity only, direct that extremity, which is destitute of chlorophyll or green coloring-matter, toward the light. Closely resembling these zoospores are the "spermatozoa" of the higher orders of cryptogamic plants, ferns, equisetums, and mosses. These bodies (Fig. 2) are produced in the antheridia or male organs, again by a modification of the protoplasmic cell-contents ”

“ The pollen is thus thrown on to the head or body of the insect, which carries it away to the next flower it visits, and leaves some of it on the stigma, and thus cross-fertilization instead of self-fertilization is secured. ”

“ When released from the parent-cells, they move about with great activity activity until they come into contact with the opening of the archegonium or female organ, which they enter, and thus fructify the germ of the new plant. ”

“ Similar motion of the stamens toward the pistil, but spontaneous, takes place in the case of the London Pride, and other species of Saxifraga.
Elasticity is, indeed, a common property of organized tissue, though it is not often developed to so evident an extent. ”