Popular Science Monthly/Volume 40/December 1891/Some of the Possibilities of Economic Botany II
|SOME OF THE POSSIBILITIES OF ECONOMIC BOTANY.|||
By GEORGE LINCOLN GOODALE.
III. Fruits. — Botanically speaking, the cereal grains of which we have spoken are true fruits, that is to say, are ripened ovaries, but for all practical purposes they may be regarded as seeds. The fruits, of which mention is now to be made, are those commonly spoken of in our markets as fruits.
First of all, attention must be called to the extraordinary changes in the commercial relations of fruits by two direct causes:
- (1) The canning industry, and —
- (2) Swift transportation by steamers and railroads.
The effects of these two agencies are too well known to require more than this passing mention. By them the fruits of the best fruit-growing countries are carried to distant lands in quantities which surprise all who see the statistics for the first time. The ratio of increase is very startling. Take, for instance, the figures given by Mr. Morris at the time of the great Colonial and Indian Exhibition in London. Compare double decades of years:
In the Colonial Exhibition at London, in 1886, fruits from the remote colonies were exhibited under conditions which proved that, before long, it may be possible to place such delicacies as the cherimoyer, the sweet-cup, sweet-sop, rambutan, mango, and mangosteen at even our most northern seaports. Furthermore, it seems to me likely that, with an increase in our knowledge with regard to the microbes which produce decay, we may be able to protect the delicate fruits from injury for any reasonable period. Methods which will supplement refrigeration are sure to come in the very near future, so that, even in a country so vast as our own, the most perishable fruits will be transported through its length and breadth without harm.
The canning industry and swift transportation are likely to diminish zeal in searching for new fruits, since, as we have seen in the case of the cereals, we are prone to move in lines of least resistance and leave well enough alone.
To what extent are our present fruits likely to be improved? Even those who have watched the improvement in the quality of 2o8 THE POPULAR SCIENCE MONTHLY.
some of our fruits, like oranges, can liardly realize how great has been the improvement within historic times in the character of certain pears, apples, and so on.
The term historic is used advisedly, for there are prehistoric fruits which might serve as a point of departure in the consider- ation of the question. In the ruins of the lake-dwellings in Switz- erland * charred apples have been found, which are, in some cases, plainly of small size, hardly equaling ordinary crab-apples. But, as Dr. Sturtevant has shown, in certain directions there has been no marked change of type ; the change is in quality.
In comparing the earlier descriptions of fruits with modern accounts it is well to remember that the high standards by which fruits are now judged are of recent establishment. Fruits which would once have been esteemed excellent would to-day be passed by as unworthy of regard.
It seems probable that the list of seedless fruits will be mate- rially lengthened, provided our experimental horticulturists make use of the material at their command. The common fruits which have very few or no seeds are the banana, pineapple, and certain oranges. Others mentioned by Mr. Darwin as well known are the bread-fruit, pomegranate, azarole or Neapolitan medlar, and date palms. In commenting upon these fruits, Mr. Darwin t says that most horticulturists " look at the great size and anomalous devel- opment of the fruit as the cause and sterility as the result," but he holds the opj^osite view as more probable — that is, that the sterility, coming about gradually, leaves free for other growth the abundant supply of building material which the forming seed would otherwise have. He admits, however, that " there is an an- tagonism between the two forms of reproduction, by seeds and by buds, when either is carried to an extreme degree, which is inde- pendent of any incipient sterility."
Most plant-hybrids are relatively infertile, but by no means wholly sterile. With this sterility there is generally augmented vegetative vigor, as shown by Nageli. Partial or complete steril- ity and corresponding luxuriance of root, stem, leaves, and flower may come about in <>ther obscure ways, and such cases are famil- iar to botanists.J Now, it seems highly probable that, either by hybridizing directed to this special end, or by careful selection of
- Carbonized apples have been found at Wangen, sometimes whole, sometimes cut in
two, or, more rarely, into four pieces and evidently dried and put aside for winter use. .... They are small and jrenerally resemble those which still ^row wild in the Swiss forests ; at Robenhausen, however, specimens have occurred which are of larger size, and probably cultivated. No trace of the vine, the walnut, the cherr}', or the damson has yet been met with, but stones of the wild plum and the Primus padus have been found." Lubbock, loe. cit., p. 217.
f Animals and Plants under Domestication (American edition), vol. ii, p. 205-209.
X Gray's Botanical Text Rook, vols, i and ii.
�� � POSSIBILITIES OF ECONOMIC BOTANY. 209
forms indicating this tendency to tlie correlated changes, we may succeed in obtaining important additions to our seedless or nearly seedless plants. Whether the ultimate profit would be large enough to pay for the time and labor involved is a question which we need not enter into ; there appears to me no reasonable doubt that such efforts would be successful. There is no reason in the nature of things why we should not have strawberries without the so-called seeds ; blackberries and raspberries, with only deli- cious pulp ; and large grapes as free from seeds as the small ones which we call " currants," but which are really grapes from Corinth.
These and the coreless apples and pears of the future, the stone- less cherries and plums, like the common fruits before mentioned, must be propagated by bud division, and be open to the tendency to diminished strength said to be the consequence of continued bud-propagation. But this bridge need not be crossed until we come to it. Bananas have been perpetuated in this way for many centuries, and pineapples since the discovery of America, so that the borrowed trouble alluded to is not threatening. First we must catch our seedless fruits.
Which of our wild fruits are promising subjects for selection and cultivation ?
Mr. Crozier, of Michigan, has pointed out * the direction in which this research may prove most profitable. He enumerates many of our small fruits and nuts which can be improved.
Another of our most careful and successful horticulturists believes that the common blueberry and its allies are very suit- able for this purpose and offer good material for experimenting. The sugar^plum, or so-called shadbush, has been improved in many particulars, and others can be added to this list.
But again we turn very naturally to Japan, the country from which our gardens have received many treasures. Referring once more to Prof. Georgeson's studies,! we must mention the varieties of Japanese apples, pears, peaches, plums, cherries, and persim- mons. The persimmons are already well known in some parts of our country under the name " kaki," and they will doubtless make rapid progress in popular favor.
The following are less f amilar : Actinidia arguta and volubilis, with delicious berries ;
Sfaunfonia, an evergreen vine yielding a palatable fruit ;
Mijrica rubra, a small tree with an acidulous, juicy fruit ;
ElcBagnus umhellata, with berries for preserves.
The active and discriminating horticultural journals in America and Europe are alive to the possibilities of new Japanese fruits,
- American Garden, New York. 1890-'91. f Ibid. 1891.
VOL. XL. — 17
�� � 210 THE POPULAR SCIENCE MONTHLY.
and it can not be very long before our list is considerably in- creased.
It is absolutely necessary to recollect that in most cases varia- tions are slight. Dr. Masters and Mr. Darwin have called atten- tion to this and have adduced many illustrations, all of which show the necessity of extreme patience and caution. The general student curious in such matters can have hardly any task more instructive than the detection of the variations in such common plants as the blueberry, the wild cherry, or the like. It is an ex- cellent preparation for a practical study of the variations in our wild fruits suitable for selection.
It was held by the late Dr. Gray that the variations in Nature by which species have been evolved were led along useful lines — a view which Mr. Darwin regretted he could not entertain. How- ever this may be, all acknowledge that by the hand of the culti- vator variations can be led along useful lines ; and, furthermore, the hand which selects must uphold them in their unequal strife. In other words, it is one thing to select a variety and another to assist it in maintaining its hold upon existence. Without the constant help of the cultivator who selects the useful variety, there comes a reversion to the ordinary specific type which is fitted to cope with its surroundings.
I think you can agree with me that the p'rospect for new fruits and for improvements in our established favorites is fairly good.
IV. Timbers and Cabinet Woods. — Can we look for new timbers and cabinet woods ? Comparatii^ely few of those in com- mon use are of recent introduction. Attempts have been made to bring into great prominence some of the excellent trees of India and Australia which furnish wood of much beauty and timber of the best quality. A large projDortion of all the timbers of the South Seas are characterized by remarkable firmness of texture and high specific gravity.* The same is noticed in many of the woods of the Indies. A few of the heavier and denser sorts, like jarrah, of West Australia, and sabicu, of the Caribbean Islands, have met with deserved favor in England, but the cost of trans- portation militates against them. It is a fair question whether in certain parts of our country these trees and others which can be utilized for veneers may not be cultivated to advantage. Atten- tion should be again called to the fact that many plants succeed far better in localities which are remote from their origin, but where they find conditions substantially like those which they have left. This fact, to which we must again refer in detail with regard to certain other classes of plants, may have some bear-
- Useful Native Plants of Australia. By J. H. Maiden, Sydney.
�� � POSSIBILITIES OF ECONOMIC BOTANY. 211
ing -upon the introduction of new timber trees. Certain draw- backs exist with regard to the timber of some of the more rapidly growing hard-wood trees which have prevented their taking a high place in the scale of values in mechanical engineering.
One of the most useful soft-wooded trees in the world is the kauri. It is restricted in its range to a comparatively small area in the North Island of New Zealand. It is now being cut down with a recklessness which is as prodigal and shameful as that which has marked our own treatment of forests here. It should be said, however, that this destruction is under protest ; in spite of which it would seem to be a question of only a few years when the great kauri groves of New Zealand will be a thing of the past. Our energetic Forest Department has on its hands problems just like this which perplexes one of the new lands of the South. The task in both cases is double : to preserve the old treasures and to bring in new.
The energy shown by Baron von Mueller, the renowned Gov- ernment Botanist of Victoria, and by various forest departments in encouraging the cultivation of timber trees will assuredly meet with success ; one can hardly hope that this success will appear fully demonstrated in the lifetime of those now living, but I can not think that many years will pass before the promoters of such enterprises may take fresh courage.
In a modest structure in the city of Sydney, New South Wales, Mr. Maiden* has brought together, under great dilficulties, a large collection of the useful products of the vegetable kingdom as represented in Australia. It is impossible to look at the collec- tion of woods in that museum, or at the similar and more showy one in Kew, without believing that the field of forest culture must receive rich material from the southern hemisphere.
Before leaving this part of our subject it may be well to take some illustrations in passing, to show how important is the influ- ence exerted upon the utilization of vegetable products by causes which may at first strike one as being rather remote.
1. Photography makes use of the effect of light on chroma- tized gelatin to produce under a negative the basis of relief plates for engraving. The degree of excellence reached in modi- fications of this simple device has distinctly threatened the very existence of wood-engraving, and hence follows a diminished de- gree of interest in box-wood and its substitutes.
2. Iron, and in its turn steel, is used in ship-building, and this renders of greatly diminished interest all questions which concern the choice of the different oaks and similar woods.
3. But, on the other hand, there is increased activity in certain
- Useful Native Plants of Australia. By J. H. Maiden, Sydney.
�� � 212 THE POPULAR SCIENCE MONTHLY.
directions, best illustrated by the extraordinary development of the cbemical methods for manufacturing wood-pulp. By the im- proved processes, strong fibers suitable for fine felting on the screen and fit for the best grades of certain lines of paper are given to us from rather inferior sorts of wood. He would be a rash prophet who should venture to predict what will be the future of this wonderful industry, but it is plain that the time is not far distant when acres now worthless may be covered by trees under cultivation growing for the pulp-maker.
There is no department of economic botany more promising in immediate results than that of arboriculture.
V. Vegetable Fibers. — The vegetable fibers known to com- merce are either plant-hairs, of which we take cotton as the type, or filaments of bast-tissue, represented by flax. No new plant- hairs have been suggested which can compete in any way for spinning with those yielded by the species of Gossijpium, or cot- ton, but experiments more or less systematic and thorough are being carried on with regard to the improvement of the varieties of the species. Plant-hairs for the stuffing of cushions and pillows need not be referred to in connection with this subject.
Countless sorts of plants have been suggested as sources of good bast-fibers for spinning and for cordage, and many of these make capital substitutes for those already in the factories. But the questions of cheapness of production, and of subsequent prep- aration for use, have thus far militated against success. There may be much difference between the profits promised by a labora- tory experiment and those resulting from the same process con- ducted on a commercial scale. The existence of such differences has been the rock on which many enterprises seeking to intro- duce new fibers have been wrecked.
In dismissing this portion of our subject it may be said that a process for separating fine fibers from undesirable structural elements, and from resin-like substances which accompany them, is a great desideratum. If this were supplied, many new species would assume great prominence at once.
VI. Tanning Materials. — What new tanning materials can be confidently sought for ? In his Useful Native Plants of Australia, Mr. Maiden * describes over thirty species of " wattles " or Acacias, and about half as many Eucalypts, which have been examined for the amount of tanning material contained in the bark. In all, eighty-seven Australian species have been under examina- tion. Besides this, much has been done looking in the same direc- tion at the suggestion and under the direction of Baron von Mueller, of Victoria. This serves to indicate how great is the
- Useful Native Plants of Australia. By C. H. Maiden, Sydney.
�� � POSSIBILITIES OF ECONOMIC BOTANY. 213
interest in this subject, and how wide is the field in onr own country for the introduction of new tanning plants.
It seems highly probable, however, that artificial tanning sub- stances will at no distant day replace the crude matters now employed.
VII. Resins, etc. — Resins, oils, gums, and medicines from the vegetable kingdom would next engage our attention if they did not seem rather too technical for this occasion, and to possess an interest on the whole somewhat too limited. But an allied sub- stance may serve to represent this class of products and indicate the drift of present research.
India Rubber* — Under this term are included numerous sub- stances which possess a physical and chemical resemblance to each other. An Indian Ficus, the early source of supply, soon became inadequate to furnish the quantity used in the arts even when the manipulation of rubber was almost unknown. Later, supplies came from Hevea of Brazil, generally known as Para rubber, and from Castilloa, sometimes called Central American rubber, and from Maniliot Glaziovii, Ceara rubber. Not only are these plants now successfully cultivated in experimental gardens in the tropics, but many other rubber-yielding species have been added to the list. The Landolpliias are among the most promising of the whole : these are the African rubbers. Now, in addition to these, which are the chief source of supply, we have Willughbeia, from the Malayan Peninsula, Leuconotis, Chilocarpus, Alstonia, Fors- teronia, and a species of a genus formerly known as Urostigma, but now united with Ficus. These names, which have little sig- nificance as they are here pronounced in passing, are given now merely to impress upon our minds the fact that the sources of a single commercial article may be exceedingly diverse. Under these circumstances search is being made not only for the best varieties of these species but for new species as well.
There are few excursions in the tropics which possess greater interest to a botanist who cares for the industrial aspects of plants than the walks through the garden at Buitenzorg in Java and at Singapore. At both these stations the experimental gardens lie at some distance from the great gardens which the tourist is ex- pected to visit, but the exertion well repays him for all discomfort. Under the almost vertical rays of the sun are here gathered the rubber-yielding plants from different countries, all growing under conditions favorable for decisions as to their relative value. At Buitenzorg a well-equipped laboratory stands ready to answer practical questions as to quality and composition of their products, and year by year the search extends.
��* See note (*), p. 11.
�� � 214 THE POPULAR SCIENCE MONTHLY.
I mention this not as an isolated example of what is being ac- complished in commercial botany, but as a fair illustration of the thoroughness with which the problems are being attacked. It should be further stated that at the garden in question assiduous students of the subject are eagerly welcomed and are provided with all needed appliances for carrying on technical, chemical, and pharmaceutical investigations. Therefore I am justified in saying that there is every reason for believing that in the very near fu- ture new sources of our most important products will be opened up, and new areas placed under successful cultivation.
At this point attention must be called to a very modest and convenient hand-book on the Commercial Botany of the Nineteenth Century, by Mr. Jackson, of the Botanical Museum attached to the Royal Gardens, Eew, which not only embodies a great amount of well-arranged information relative to the new useful plants, but is, at the same time, a record of the existing state of things in all these departments of activity.
VIII. Fragrant Plants.— Another illustration of our subject might be drawn from a class of plants which repays close study from a biological point of view, namely, those which yield per- fumes.
In speaking of the future of our fragrant plants we must dis- tinguish between those of commercial value and those of purely horticultural interest. The former will be less and less cultivated in proportion as synthetic chemistry by its manufacture of per- fumes replaces the natural by the artificial products, for example, coumarin, vanillin, nerolin, heliotropin, and even oil of winter- green.
But do not understand me as intimating that chemistry can ever furnish substitutes for living fragrant plants. Our gardens will always be sweetened by them, and the possibilities in this direction will continue to extend both by contributions from abroad and by improvement in our present cultivated varieties. Among the foreign acquisitions are the fragrant species of Andro- pogon. Who would suspect that the tropical relatives of our sand- loving grasses are of high commercial value as sources of per- fumery oils ?
The utility to the plant of fragrance in the flower, and the relation of this to cross-fertilization, are apparent to even a casual observer. But the fragrance of an aromatic leaf does not always give us the reason for its being.
It has been suggested for certain cases that the volatile oils escaping from the plants in question may, by absorption, exert a direct influence in mitigating the fierceness of action of the sun's rays. Other explanations have also been made, some of which are even more fanciful than the last.
�� � POSSIBILITIES OF ECONOMIC BOTANY. 215
When, however, one has seen that the aromatic plants of Aus- tralia are almost free from attacks of insects and fungi, and has learned to look on the impregnating substances in some cases as protective against predatory insects and small foes of all kinds, and in others as fungicidal, he is tempted to ask whether all the substances of marked odor which we find in certain groups of plants may not play a similar role.
It is a fact of great interest to the surgeon that in many plants there is associated with the fragrant principle a marked antiseptic or fungicidal quality ; conspicuous examples of this are afforded by species of eucalyptus, yielding eucalyptol; Styrax, yielding styrone ; Thymus, yielding thymol. It is interesting to note, too, that some of these most modern antiseptics were important con- stituents in the balsamic vulneraries of the earliest surgery.
Florists' plants and the floral fashions of the future constitute an engaging subject which we can touch only lightly. It is rea- sonably clear that while the old favorite species will hold their ground in the guise of improved varieties, the new introductions will come in the shape of plants with flowering branches which retain their blossoms for a somewhat long period, and especially those in which the flowers precede the leaves. In short, the next real fashion in our gardens is probably to be the flowering shrub and flowering tree, like those which are such favorites in the country from which the Western world has gladly taken the gift of the chrysanthemum.
Twice each year, of late, a reception has been held by the Emperor and Empress of Japan. The receptions are in autumn and in the spring. That in the autumn, popularly known as the Emperor's reception, has for its floral decorations the myriad forms of the national flower, the chrysanthemum ; that which is given in spring, the Empress's reception, comes when the cherry blossoms are at their best. One has little idea of the wealth of beauty in masses of flowering shrubs and trees until he has seen the floral displays in the Imperial Gardens and the Temple grounds in Tokio.
To Japan* and China also we are indebted for many of the choicest plants of our gardens, but th& supply of species is by no means exhausted. By far the larger number of the desirable plants have already found their way into the hands of cultivators, but often under conditions which have restricted their dissemi- nation through the flower-loving community. There are many which ought to be widely known, especially the fascinating dwarf
- The Flowers of Japan and the Art of Floral Arrangement. By Josiah Conder,
F. R. I. B. A., Architect to the Imperial Japanese Government. Yokohama, 1S91. See also two other works by the same author : Theory of Japanese Flower Arrangements, and Art of Landscape Gardening in Japan. (1886.)
�� � 2i6 THE POPULAR SCIENCE MONTHLY.
shrubs and dwarf trees of the far East, which are sure to find sooner or later a warm welcome among us.
X. Forage Plants.— Next to the food-plants for man, there is no single class of commercial plants of greater interest than the food-plants for flocks and herds. Forage plants, wild and cultivated, are among the most important and highly valued re- sources of vast areas. No single question is of more vital con- sequence to our farthest West and Southwest.
It so happens that the plants on which the pastoralist relies grow or are grown on soil of inferior value to the agriculturist. Even soil which is almost sterile may possess vegetation on which flocks and herds may graze; and, further, these animals may thrive in districts where the vegetation appears at first sight too scanty or too forbidding even to support life. There are im- mense districts in parts of the Australian continent where flocks are kept on plants so dry and desert-like that an inexperienced person would pass them by as not fit for his sheep, and yet, as Mr. Samuel Dixon* has well shown, these plants are of high nutritive value and are attractive to flocks.
Eelegatiug to the notes to be published with this address brief descriptions of a few of the fodder-plants suggested for use in dry districts, I shall now mention the salt-bushes of various sorts, and the allied desert plants of Australia, as worth a careful trial on some of our very dry regions in the farthest West. There are numerous other excellent fodder-plants adapted to dry but not parched areas which can be brought in from the corresponding districts of the southern hemisphere and from the East.
At an earlier stage of this address I have had occasion to refer to Baron von Mueller, whose efforts looking toward the intro-
- Mr. Samuel Dixon's list is in vol. viii (for 1884-'85) of the Transactions and Proceed-
ings and Report of the Royal Society of South Australia. Adelaide, G. Robertson, 1886. Bursaria spinosa : " A good stand-by," after the grasses dry up. Pomaderris racemosa, " stands stocking well." Pittosporum phyllaeroides : " Sheep exceedingly partial to its foliage." Casuarina quadrivalvis : *' Tenderness of fiber of wool would be prevented by it in our finer wool districts." Acacias, the wattles : " Value as an astringent, very great," being curative of a malady often caused by eating frozen grass. Acacia aneura (mulga) : " Must be very nutritious to all animals eating it." This is the plant which is such a terror to the stockmen who have to ride through the " scrub." Cassia, some of the species with good pods and leaves for sheep. The foregoing are found in districts which are not wholly arid. The following are, more properly, " dry " plants. Sida petrophila : " As much liked by sheep as by marsupials." Dodonwaviscosa, native hop-bush : "Likes warm, red, sandy ground." Lycium amirale: " Drought never seems to affect it." Kochia aphylla : " All kinds of stock are often largely dependent on it during protracted droughts." Rhagodia parabolica : " Produces a good deal of foliage." Atriplex vesicaria : " Can be readily grown wherever the climate is not too wet." I have transferred only those which Mr. Dixon thinks most worthy of trial. Compare also Dr. Vasey's valuable studies of the plants of our dry lands, especially grasses and forage plants (1878), grasses of the arid districts of Kansas, Nebraska, and Colorado (1886), grasses of the South (1887).
�� � POSSIBILITIES OF ECONOMIC BOTANY. 217
duction of useful plants into Australasia have been aided largely by bis convenient treatise on economic plants.* It may be said in connection with the fodder-plants, especially, that much which the baron has written can be applied mutatis mutandis to parts of our own country.
The important subject of introducing fodder-plants has been purposely reserved to the last because it permits us to examine a practical point of great interest. This is the caution which it is thought necessary to exercise when a species is transferred by our own choice from one country to another, I say by our choice, for, whether we wish it or not, certain plants will introduce themselves. In these days of frequent and intimate intercommunication be- tween different countries, the exclusion of foreign plants is simply impossible. Our common weeds are striking illustrations of the readiness with which plants of one country make for themselves a home in another, f All but two of the prominent weeds of the Eastern States are foreign intruders.
There are all grades of persistence in these immigrants. Near the ballast grounds of every harbor, or the fields close by woolen and paper mills where foreign stock is used, you will observe many foreign plants which have been introduced by seed. For many of these you will search in vain a second year. A few others persist for a year or two longer, but with uncertain tenure of the land which they have invaded ; others still have come to stay. But happily some of the intruders, which seem at first to gain a firm foothold, lose their ground after a while. We have a conspicuous example of this in a hawkweed, which was very threatening in New England two years ago, but is now relaxing its hold.
Another illustration is afforded by a water-plant which we have given to the Old "World. This plant, called in our botanies Anacliaris, or Elodea, is, so far as I am aware, not troublesome in our ponds and water-ways, but when it was carried to England, perhaps as a plant for the aquarium, it was thrown into streams and rivers with a free hand. It spread with remarkable rapidity and became such an unmitigated nuisance that it was called a curse. Efforts to extirpate it merely increased its rate of growth. Its days of mischief are, however, nearly over, or seem to be draw- ing to a close ; at least so Mr. Lynch, of the Botanic Garden in Cambridge, England, and others of my informants think. The history of the plant shows that even under conditions which, so
- See note, p. 59.
f The weeds of German gardens and agricultural lands are mostly from Mediterranean regions, but the invasions in the uncultivated districts are chiefly from America (such as (Enothcra^ MimuJus, Ricdheckia). Handbuch der PJlanzengeograpJiie, von Dr. Oscar Drude (Stuttgart), 1890, p. 97.
�� � 2i8 THE POPULAR SCIENCE MONTHLY.
far as we can see, are identical with, those under which the plant grew in its home, it may for a time take a fresh, lease of life and thrive with an undreamed-of energy.
What did Anacharis find in the waters of England and the Continent that it did not have at home, and why should its energy begin to wane now ?
In Australasia one of the most striking of these intruders is sweet-brier. Introduced as a hedge plant, it has run over certain lands like a weed, and disputes every acre of some arable plats. From the facility with which it is j)ropagated it is almost in- eradicable. There is something astounding in the manner in which it gains and holds its ground. Gorse and brambles and thistles are troublesome in some localities, and they prove much less easy to control than in Europe. The effect produced on the mind of the colonist by these intruding pests is everywhere the same. Whenever, in an examination of the plants likely to be worthy of trial in our American dry lands, the subject was men- tioned by me to Australians, I was always enjoined to be cautious as to what plants I might suggest for introduction from their country into our own. My good friends insisted that it was bad enough to have as pests the plants which come in witliout our planning or choice, and this caution seems to me one which should not be forgotten.
It would take us too far from our path to inquire what can be the possible reasons for such increase of vigor and fertility in l^lants which are transferred to a new home. We should have to examine all the suggestions which have been made, such as fresh soil, new skies, more efficient animal friends, or less destructive enemies. We should be obliged also to see whether the possible wearing out of the energy of some of these plants after a time might not be attributable to the decadence of vigor through un- interrupted bud-propagation, and we should have to allude to many other questions allied to these. But for this time fails.
Lack of time also renders it impossible to deal w^ith the ques- tions which attach themselves to our main question, especially as to the limits of effect which cultivation may produce. We can not touch the problem of inheritance of acquired peculiarities, or the manner in which cultivation predisposes the plant to innu- merable modifications. Two of these modifications may be men- tioned in passing, because they serve to exemplify the practical character of our subject.
Cultivation brings about in plants very curious morphological changes. For example, in the case of a well-known vegetable the number of metamorphosed type-leaves forming the ovary is two, and yet under cultivation the number increases irregularly until the full number of units in the type of the flower is reached.
�� � POSSIBILITIES OF ECONOMIC BOTANY. 219
Prof Bailey, of Cornell, has called attention to some further in- teresting changes in the tomato, but the one mentioned suffices to illustrate the direction of variation which plants under culti- vation are apt to take. Monstrosities are very apt to occur in cultivated plants, and under certain conditions may be perpetu- ated in succeeding generations, thus widening the field from which utilizable plants may be taken.
Another case of change produced by cultivation is likewise as yet wholly unexplained, although much studied, namely, the mu- tual interaction of scion and stock in grafting, budding, and the like. It is probable that a further investigation of this subject may yet throw light on new possibilities in plants.
We have now arrived at the most practical question of all,
namely— . j j
In what way can the range of commercial botany be extended .-' In what manner or by what means can the introduction of new species be hastened ?
It is possible that some of you are unaware of the great amount of uncoordinated work which has been done and is now in hand in the direction of bringing in new plants.
The competition between the importers of new plants is so great both in the Old World and the New that a very large pro- portion of the species which would naturally commend them- selves for the use of florists, for the adornment of greenhouses, or for commercial ends, have been at one time or another brought before the public or are being accumulated in stock. The same is true, although to a less extent, with regard to useful vegetables and fruit. Hardly one of those which we can suggest as desirable for trial has not already been investigated in Europe or this country, and reported on. The pages of our chemical, pharma- ceutical, medical, horticultural, agricultural, and trade journals, especially those of high grade, contain a wealth of material of this character.*
But what is needed is this, that the promising i^lants should be systematically investigated under exhaustive conditions. It is not enough that an enthusiast here, or an amateur there, should give a plant a trial under imperfectly understood conditions, and then report success or failure. The work should be thorough and every question answered categorically, so that we might be placed in possession of all the facts relative to the object experimented upon. But such an undertaking requires the co-operation of many different agencies. I shall venture to mention some of these. In the first place— botanic gardens amply endowed for re-
��* The list of economic plants published by the department in Washington is remark- ably full, and is in every way creditable to those in charge.
�� � 220 THE POPULAR SCIENCE MONTHLY.
searcli. The Arnold Arboretum, the Shaw Garden, and the Washington Experimental Garden are American illustrations of what is needed for this purpose. University gardens have their place in instruction, but can not wisely undertake this kind of work.
In the second place — museums and laboratories of economic botany. Much good work in this direction has been done in this country by the National Museum and by the department in charge of the investigation of new plants. "We need institu- tions like those at Kew in England, and at Buitenzorg in Java, which keep in close touch with all the world. The founding of an establishment on a scale of magnitude commensurate with the greatness and needs of our country is an undertaking which waits for some one of our wealthy men.
In the third place — experiment stations. These may, within the proper limits of their sphere of action, extend the study of plants beyond the established varieties to the species, and beyond the species to equivalent species in other genera. It is a matter of regret that so much of the energy displayed in these stations in this country, and we may say abroad, has not been more eco- nomically directed.
Great economy of energy must result from the recent change by which co-ordination of action is assured. The influence which the stations must exert on the welfare of our country and the de- velopment of its resources is incalculable.
In the last place, but by no means least, the co-operation of all who are interested in scientific matters, through their observation of isolated and associated phenomena connected with plants of supposed utility, and by the cultivation of such plants by private individuals, unconnected with any State, governmental, or aca- demic institutions.
By these agencies, wisely directed and energetically employed, the domains of commercial and industrial botany will be en- larged. To some of the possible results in these domains I have endeavored to call your attention.
��The stock of diamonds, according to the calculations of Iron, has increased enormously during the past fifteen years. The product of the African mines, 1,500,000 carats in 1876, was 4,000,000 carats in 1889. Still, the demand for diamonds increases, and the price rises every year. The traffic in diamonds is essentially different from all other trades in the single item that the product is never consumed. While there is a perceptible wear even in gold and silver, a diamond, once cut, is permanently added to the stock, and is liable to come upon the market at any time. Yet a place and eager purchasers are found for all the new ones.
- Presidential address delivered before the American Association for the Advancement of Science, at Washington, August, 1891.