1. Respiration. 2. Circulation. 3. Nutrition. 4. Digestion of animal food. 5. Secretion including a solvent juice resembling the gastric. 6. Absorption. 7. Luminosity. 8. Evolution of heat. 9. Presence of electric currents.* 10. Sleep. 11. Exhaustion with reinvigoration after rest. 12. Spontaneous movements. 13. Same kinds of Diseases. 14. Same influence of atmospheric or gaseous Poisons. 15. Same results of chemical or mechanical Irritation. 16. Same effects of light and darkness, and of heat and cold. 17. Contractility-analogous to muscular. 18. Heredity. 19. Mimicry. It would be improper here to do more than merely refer to some of these phenomena, en passant. For details the reader is referred to the various botanical and other works quoted or mentioned in the text or foot-notes. Quite recently Prof. Leidy, in a paper on the "Moving Power of Diatoms, Desmids, and other Algæ,"+ has shown how this power of spontaneous or automatic movement enables them, when mixed with mud, to extricate themselves and rise to the surface. He describes them as very active-gliding hither and thither. These active movements, are, however, more familiar in the Zoospores of Algae and Lichens; and they occur also in the Bacteria, which figure so prominently in current discussions regarding Spontaneous Generation and the Germ-theory of disease. Solar heat and light-or their absence-artificial as well as natural heat, light, and darkness-exercise the same sort of influence over plants as on animals. Nearly twenty years ago I showed-especially in regard to Cholera-that plants, and animals including man, are equally subject, mutatis mutandis, to all atmospheric influences * As demonstrated more especially by Prof. Burdon-Sanderson, for instance, in his "Note on the Electrical Phenomena which accompany irritation of the leaf of Dionoa muscipula," in the "Proceedings of the Royal Society," No. 147, 1873 which phenomena I had the pleasure of seeing for myself, when he showed them before the British Medical Association at Edinburgh, in August, 1875. Read to the Academy of Natural Sciences of Philadelphia, in September, 1874, and reported in "Nature," for June 3, 1875, p. 100. healthy or morbid, including the Epidemic ærial Poisons of whatever nature. In other words, they all alike are subject to virtually the same epidemic diseases. An admirable series of articles on Vegetable Pathology will be found in the "Gardeners' Chronicle" for 1856, by the veteran distinguished Fungologist-the Rev. M. J. Berkeley. He discourses, for instance, on the "languor and decrepitude" of trees. He also points out the similar effects of poisons on plants and animals. Certain poisons destroy both the irritability and lives of so-called "sensitive" plants; or this irritability may be suspended by anaesthetics-by the same means, that is, by which stupor is produced in animals. Irritability, therefore, is a property only of health, or of healthy tissue. In Dr. Thos. Balfour's experiments on Dionaea muscipula, chloroform, dropped on a leaf-hair, caused immediate contraction, and closure of the leaf-or, in other words, a chemical excitant or irritant produced precisely the effect of a mechanical Not only chloroform and ether, but opium and quinine produce the same kind of effects in or on plants and animals. Narcotic and acrid poisons arrest motion in plants. Brown points out the effects of poisonous gases.†“Darwin has somewhat startled us by the announcement that, by puncturing a particular part [of the Dionaea muscipula], he has succeeded in producing a kind of hemiplegia, or one-sided paralysis.‡ one. The irritability of the hairs of Dionaea is impaired or exhausted by frequent or excessive stimulation. Exhaustion is the result of repeated excitation. The occurrence of Mind in plants is not, however, a mere matter of probability, possibility, or surmise. Plants exhibit, among others, the following phenomena, which, in man, are inseparably associated with Mind, if they are not regarded as― II. Elements or Constituents of Mind—as it occurs in Man and other Animals. 1. Sensation, Common: including Sensitiveness and Irritability, or Excitability; Feeling. 2. Excito-motor, Sensori-motor, Irrito-motor, Reflex, or Automatic, action. *(1) "Influence of the Cholera Poison on the Lower Animals and on Plants." Clinical Notes on Cholera: Association Medical Journal, 1854. (2) "Suggestions for Observations on the Influence of Cholera and other Epidemic Poisons on Plants." Proceedings of Botanical Society of Edinburgh, 1856. + "Manual of Botany: Anatomical and Physiological," Edinburgh, 1874, P. 257. Dr. Thomas A. G. Balfour, in "The Garden," for August, 1875. 3. Memory, Organic. 4. Consciousness. 5. Instinct. 6. Sympathy, Preference, Predilection or Partiality, Liking or Attachment, with their opposites. 7. Antipathy or Aversion. 8. Choice or Selection; adoption of an Alternative. 9. Volition or Will. 10. Recognition and Rectification of Error. 11. Power of Adaptation, or Accommodation, to circumstances. Including adaptive movements; appropriateness of behaviour, action or conduct; general adaptiveness or adaptivity. 12. Power of avoiding or Overcoming mechanical Obstacles or difficulties. 13. Purposive action: use of means to an End. 14. Sense of Life. 15. Polarity, or Sense of Direction.* 16. Individuality and Eccentricity. 17. Knowledge of Consequences. 18. Judgment, Discrimination, or Sense. 19. Profiting by Experience. 20. Spontaneity of Effort or attempt: Repetition thereof: and Failure. 21. Investigation and Experiment. Testing or trial. 22. Desire, Longing, or Appetite. 23. Use of Natural and Artificial Tools. 24. Calculation or Measurement of distance or space. 25. Patience. 26. Perseverance-including Resolution or Resoluteness. 27. Energy or Activity: with their opposites, Slowness, Awkwardness, Indifference, Apathy, Lethargy. 28. Caution. 29, Acquisition of Knowledge, and the suitable application thereof. It is generally admitted that Plants possess, what is called by physiologists "common sensation," identical with, or resembling, that which exists in the skin and other parts of the human body to which the sensory nerves are distributed: which sensation is excited by ordinary mechanical or chemical stimuli. In other phraseology, plants are endowed with certain of the "sensations of organic life." This power or property of Sensation includes sensitiveness or susceptibility to atmospheric changes or influences-just as in animals. Hence the opening or closure of leaves or flowers at night, or before rain. Hence the prognostication of weather-change E.g. In the so-called "Compass-plant." Vide Brown, "Manual," p. 562. by hygrometric or other Plants, such as the Pimpernel.* But the phenomena of Irritability render it probable that certain plants, at least, possess a special sense of Touch; and some sense or senses that take the place of those of smell, vision, and taste. Or, how else do carnivorous plants learn that digestible food is in their power or in their neighbourhood? For it is by no means necessary to such knowledge that food comes into mechanical contact with the plant-surface. No doubt plants may, and probably do, possess-as do the lower animals, and man himself-certain unknown, or unexplained faculties-powers, of the nature of which we at present know little or nothing, and which may even belong to the category of the unknowable. Using the term in its physical sense, plants possess various shades of keenness and bluntness of feeling, or sensitiveness. Under certain circumstancesnatural, or artificial-they exhibit various degrees of Insensibility, Insensitiveness or non-sensitiveness; e.g. to irritation, or the influence of stimuli-mechanical or chemical. Now, it is either extremely difficult, or altogether impossible, to dissociate sensation from mind, intellect, or consciousness. Professor Bain thinks that "sensation without intellect, is a mere abstraction. It is never realised in fact." "We cannot suppose the existence of mere sensation, without supposing that there is something more"-says the late Sir Benjamin Brodie in his " Psychological Inquiries." "All animals possess consciousness-that is have sensations"-says Lewes and in this sense so must plants possess Consciousness. Dr. Carpenter, in common with Lewes and other authors, holds that "sensations are, indeed, but states or forms of consciousness-just as much so as are ideas and emotions." Professor Laycock speaks of "ancestral endowments manifested in all organisms, whether they be plants or animals, and whether manifested as energies or functions, or states of consciousness." Purposive action-movements, having a definite and intelligible object, aim, or end in view-involving, apparently, intention or design-and possibly even motive and will-are most familiar in the phenomena of prey-capture by such plants as the Dionaea muscipula. In its case there is trapping of the most efficient kind; insomuch so, that its common English name is Venus' Fly-trap. Dr. Hooker goes the length *Brown, "Manual," p. 567. + Article "Sensation," in "Chambers's Encyclopedia," 1st ed., 1866. "Organic Laws," p. 157. of saying of Darlingtonia: "It is conceivable that this marvellous plant lures insects to its flowers for one object, and feeds them while it uses them to fertilize itself; and that, this accomplished, some of its benefactors are thereafter lured to its pitchers for the sake of feeding itself."* His description does not necessarily imply a belief that there is conscious luring or object-his expressions being, presumably, figurative.t Dr. Carpenter obviously regards prehension of prey or food by Dionaea or Drosera, as a merely mechanical, automatic, or reflex, non-conscious act. "Just as mechanically," says he, "as the fly-trap of the Dionaea closes upon the unlucky insect that alights upon it, so do a frog's legs act, although the spinal cord has been divided both above and below the segment from which the nerves of the fore-legs are given off."+ He is here drawing a parallel between the fore-legs of a male frog at the season of sexual excitement-which "tend to close firmly upon anything that is placed between them and will retain that clasp for weeks"—and Dionaea in its seizure of insects or other bodies. But the parallelism is an unfortunate one. In both cases he omits all reference to the choice of the object upon which to contract; in the one case the female frog, in the other nutrient, albuminoid, nitrogenous substances. In the one case, as in the other, the legs or leaf margins may contract, under exceptional circumstances, upon "anything that is placed between them." But, so far as concerns at least the Dionaea, this does not always happen; and, when it does, it is to be attributed to an error which the plant not only discovers, but rectifies. There can be no doubt that, as a rule, it distinguishes between suitable and unsuitable food, or rather between bodies which may supply food on the one hand, or are incapable of doing so on the other. This eclecticism, selection or choice, can scarcely be set down, even by Dr. Carpenter, as "mechanical." He, himself, however, feels bound to admit, with regard to the frog, that "a few physiologists" still "credit the spinal cord of the frog with the power of conscious selfdirection." He draws attention to the fact that the headless * Address on "The Carnivorous Habits of Plants," delivered at the British Association Meeting at Belfast, 1874, and reported in "Nature," September 3, 1874, p. 370. Just as such terms as sleep, love and soul, are used figuratively by at least the majority of those who employ them at all in regard to Plants. "On the Doctrine of Human Automatism."-Contemporary Review, Feb., 1875, p. 410. § Ibid, p. 412. |