FREAKS AND MARVELS OF PLANT LIFE; OR, CURIOSITIES OF VEGETATION.
<!-- image -->BY M. C. COOKE, M.A., LL.D.
AUTHOR OF "PONDS AND DITCHES," "THE WOODLANDS," ETC. ETC.
FOURTH THOUSAND.
PUBLISHED UNDER THE DIRECTION OF THE COMMITTEE OF GENERAL LITERATURE AND EDUCATION APPOINTED BY THE SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE.
LONDON: SOCIETY FOR PROMOTING CHRISTIAN KNOWLEDGE, NORTHUMBERLAND AVENUE, CHARING CROSS, S.W.; 43, QUEEN VICTORIA STREET, E.C.; 48, PICCADILLY, W.; AND 135, NORTH STREET, BRIGHTON.
NEW YORK: E. & J. B. YOUNG & CO. 1882.
CONTENTS
LIST OF ILLUSTRATIONS
PAGE
FREAKS OF PLANT LIFE
CHAPTER I
INTRODUCTION.
THIS work has been undertaken for the purpose of presenting in a popular form, devoid as much as possible of technical language, some of the most prominent features in the investigations which have of late years contributed so much to our knowledge of the phenomena of vegetable life. The labours especially of Mr. Darwin in this direction deserve to be more generally known than they are. Unfortunately, the dread which non-scientific persons exhibit at the outside of a scientific book often prevents any attempt at understanding its contents. Hence we have made an effort to summarise the results of these and similar experiments, and to present in as succinct a manner as the subjects permitted, their teachings. Some elaborate investigations, as, for instance, those on fertilisation, are chiefly of interest to botanists, and could be little understood or appreciated by the general public; these have, therefore, not been considered as falling within the limits of this volume. On the other hand, chapters are introduced on subjects which have not yet been submitted to exhaustive examination, but which have, nevertheless, great popular interest and fall legitimately within the scope of the title. Free use has been made of all sources of information, under the conviction that the better these experiments are known and understood, the greater and more general will be the appreciation of the labours of those who have contributed so much to the elucidation of obscure phenomena in plant-life.
Text-books remind us of the importance of the vegetable world in its relationship to the animal. They also illustrate the grandeur and beauty which the plant has conferred on the world. It is difficult to form any adequate conception of the vast extent and unlimited variety of vegetable life. All we can do is to pick up here and there some object of special interest, gaze at it, marvel at it, try to comprehend it, if we can, and then pass on, leaving behind us a trackless ocean of wonderful things, to be picked up by our successors, and marvelled at as we have done. It will be very long before the storehouse is exhausted.
We learn to appreciate what has been written of wild forests only by experience. "A very similar feeling (to that of a sea-voyage) possesses the traveller as he penetrates an extensive forest. Every morning he commences his journey, patiently pursuing the winding pathways through interminable multitudes of trees and shrubs, till, when evening arrives, he is hardly less fatigued with the monotony of the scene than with the exertions of the day. His feelings are the same as those at sea—he is surprised at the interminable character of the scene, and his ideas of space are measured by a greater standard. He wonders at the vast multitudes of vegetable beings; whence they could possibly have drawn nourishment to rear such solid structures; he speculates on their age, and lastly on their use. In both cases the ideas of space are the same, but they have received an impulse from the novelty of the scene; perhaps assisted also by the perfect stillness, which reigns so completely in deep forests, and during the heat of the day the silence is more painful than on the wide ocean. The chief difference between the two is that one is a sea of waters, the other a sea of trees." 1
It is a very natural inquiry, and one which may be fairly considered as a prelude to a subject such as ours, what number of different kinds, or species, of plants are supposed to be found on the surface of the globe? This is a question which has been propounded before, and more than once its solution has been attempted. The history of these progressive estimates is rather a curious one. It commences 390 B.C. with Theophrastus, and he enumerated 500 kinds of plants. This may be presumed to represent all that were then known. The botanical knowledge of King Solomon had, then, comparatively narrow limits, even though he discoursed on all plants from the cedar of Lebanon to the hyssop on the wall. Pliny (A.D. 79) increased the number of plants to double that of his predecessor. In the beginning of the seventeenth century the number had increased to 6,000. The second edition of Linnæus's great book included no more than 8,800. Willdenow, up to 1807, had detected 17,457 species of flowering plants. From this period the increase in the number of known species was very rapid, as a result of the stimulus given to botany by Linnæus and his successors, so that at the beginning of the present century Robert Brown had calculated the flowering plants at 37,000, and Humboldt all plants, flowering and non-flowering, at 44,000.
Progressing still further down the stream of time, in 1820, De Candolle calculated that at the least 56,000 species of plants were known. It was found that the number of species preserved in the Herbarium at the Jardin des Plantes was estimated at the same figure, and that the collection of M. Delessert contained as many as 86,000 species in 1847, although Dr. Lindley had estimated in 1835 that all the plants in the world might be included in that number.
Humboldt entered upon a series of calculations, about this time, to show that all these estimates fell short of the number which might be supposed to exist. "Such considerations," he writes, "which I purpose developing more fully at the close of this illustration, seem to verify the ancient myth of the Zend-Avesta that the creating primeval force called forth 120,000 vegetable forms from the sacred blood of the bull." In 1845 Mr. R. B. Hinds estimated the total of phanerogamic and cryptogamic plants at 134,000 species. The next estimate we meet with is in Henfrey (1857) at 213,000, but in 1855 De Candolle had, by another process of reasoning, come to the conclusion that the total could not be less than 375,000 for flowering plants. Doubtless, these calculations will go on increasing, as the highest is found to be inadequate to represent even the whole number of described species. At the present time the very lowest estimate of authentic species of cryptogamia cannot be less than 50,000, and probably considerably exceed that number.
Here, then, we have somewhat of an approximate idea, at what may be regarded a very low estimate, of the number of species of plants scattered over the face of the earth. It is always best in such calculations to under-estimate rather than over-estimate, and if we feel confidence in asserting that there are not less than 500,000 distinct and different species of vegetable organisms distributed over the globe, including land and water, it is because we feel satisfied that we have good grounds for believing that the number is in excess even of that which we have permitted ourselves to affirm.
Another "curiosity" is in respect to the relative sizes of plants; some we know to be very large, and others are very small, what then is the average size? It has been calculated, in the animal world, that between the largest living animal known on the one hand, and the smallest which the microscope has revealed, the middle place, between both extremes, is occupied by the common house-fly. If we pursue a similar plan with plants, and estimate the smallest flowering plant to be the little Duckweed (Lemna minor), and the largest a Eucalyptus tree of 420 feet, the intermediate form will be, as respects length, some such an herbaceous plant as a St. John's Wort, about 20 inches high. But if we include, as in the case of the animal world, microscopic plants, irrespective of fructification, then, with a small cellular alga, consisting of a single cell, .01 mm. in diameter, or the one two thousand five hundredth part of an inch as the lowest extreme, we shall have, in longitudinal extension only, the middle place occupied by a small moss, such as Funaria hygrometrica, with a total height of less than an inch-and-a-half. In other words, the little moss would be as many times higher than the one cell of the little green alga as the tall tree of the Eucalyptus is higher than the little moss. It would be difficult to calculate bulk for bulk, and estimate size in all directions, so as to ascertain how many such little cells as those of the alga would be required to build up the trunk of such a tree; but the number would be enormous, so far beyond human experience of numbers that the mind would fail to appreciate their relationship. The intermediate form is larger in plants than in animals, because, although there are animals as small as .01 mm., there are none reaching 420 feet in height.
Important as are the uses of plants to man, as the source of food, clothing, and medicine, it has hardly been considered as coming within the scope of this volume to refer to them in this aspect, our object being rather to present an accumulation of curious and interesting facts in the structure, habits, or phenomena of plants which have hitherto either been scattered through journals, or presented in the pages of scientific books such as the general public do not take the trouble to read. By this means we have flattered ourselves that we may possibly influence some to take a greater interest in botanical subjects, and in the phenomena of plant life, than they had previously done.
It is a fact worth remembering that vegetation may be conducive to human health and comfort in destroying malaria in pestilential districts. The planting of any "gross feeder" in such places would be beneficial, and the claims which have been advanced on behalf of the Australian gum-tree, might, to a certain extent, be urged on behalf of many other trees. Experience has proved that the planting of any trees which will thrive well and flourish in malarious places, at once produces a marked change for the better, and hygienic plantations need not be confined to the Eucalyptus. However this may be, it is interesting to note how speedily Eucalyptus globulus has found its way into the public newspapers, what patronage it has received in despite of its binomial appellation, and how its cultivation is becoming an article of faith and practice in Europe, Asia, and America, from Rome to Berlin, and from Calcutta to California. There are but few instances on record of a similar vegetable success.
In October, 1873, Mons. Gimbert narrated in "Comptes Rendus" the results of his experiments with the Eucalyptus globulus in Algeria. The tree grows rapidly and aids in destroying the malarious agency which is supposed to cause fever. It absorbs as much as ten times its weight of water from the soil, and emits camphoraceous antiseptic vapour from its leaves. A farm, some twenty miles from Algiers, was noted for its pestilential air in the spring of 1867: thirteen thousand Eucalyptus trees were planted there, since which time not a single case of fever had occurred. Numerous other like cases are cited.
The honour of discovering this property in the gum-tree is due to Sir W. Macarthur, of Sydney. But this is by no means the only use of the tree. It is valuable as a timber tree. The flowers also yield a large quantity of honey and are much frequented by bees. All parts of the tree are said to be useful as a febrifuge medicine, and the leaves when smoked are efficacious in allaying pain, calming irritation, and procuring sleep. Cigars made of the leaves were exhibited at the Paris Exhibition of 1867, and recommended as being very efficient in promoting digestion. A chemist at Melbourne also prepares cigarettes from the foliage, which he urges to be employed in bronchial and asthmatic affections. In Mauritius the leaves are sold at sixpence per ounce to make an infusion which has been administered with success in malarious fevers; and, as a reward for all these virtues, as a return for such beneficent work on behalf of humanity, this tree is now being distributed almost over the habitable globe, wherever the white man's foot has trodden.