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Entered according to Act of Congress, in the year 1875, by
CHARLES H. WALTON, In the office of the Librarian of Congress, at Washington. PUBLISHER'S PREFACE.
While bringing before the public this learned work of M. Gallesio, the translators were impressed with the fact that in some parts it might not be clear to the unscientific reader; they have, therefore, ventured to simplify and to explain botanical terms, and in some few cases geographical names.
The translation of this work was begun by Prof. S. D. Wilcox. His death occurring when but one-fourth of it was accomplished, we are consequently indebted to a friend for the completion of the task. Any discrepancy iu the style of writing may be thus accounted for.
Of all the plants spread by Nature upon the surface of the globe, there are none more beautiful than those we know under the names of citron, lemon, and orange trees, which botanists have included under the technical and generic name of Citrus. These charlhing trees are both useful and ornamental. No others equal them in beauty of leaf, delightful odor of flowers, or splendor and taste of frui£. No other plant supplies delicious confections, agreeable seasonings, perfumes, essences, syrups, and the valuable acid so useful to colorers.
In a word, these trees charm the eye, satisfy the smell, gratify the taste, serving both luxury and art, and presenting to astonished man a union of all delights.
These brilliant qualities have made the Citrus a favorite in all countries. In warm climates it is the object of careful culture, and in more temperate climes it is the necessary ornament of country-seats and villas, while, still further north, it has originated those inventions in building designed by luxury to make a summer in the midst of winter. Writers upon agriculture have occupied themselves with the cultivation and deseription, and with all tending to the preservation, propagation, and uses of these trees.
Etienne, Serres, and others in France; Gallo, Tanara, Trinci, and Ferraris in Italy; llerrara.in Spain; Miller in England; Commelyn in Belgium; Volcamerius and Sicler in Germany, have all written upon these plants. Volcamerius and Ferraris have added to their books numerous drawings of the varieties known in their time, thus seeming to leave nothing to be desired on this subject. But, after close study and thought, I have found great confusion and want of method in their classification. This is owing to the prejudices among writers concerning the nature and origin of varieties. I have, therefore, devoted myself to the close observation of these plants, examining their caprices from their birth to their fruiting, and, seconding m Nature by culture, not forcing her by the graft, 1 have been able to obtain many results, and to compare them with preceding phenomena. I have, also, attempted experiments in order to find the secret cause of these results. I have operated upon the flowers of the citrus, watching them from the moment of conception, in their development, in their fructification, and in reproduction from their seeds.
Upon observations and their consequences I have based a theory by which I have arranged my classification, definitely fixing, by decisive experiments, the species, the chief varieties, many hybrids, and nearly all the monsters. This theory I have elaborated in the first chapter of this woik, and in the second I have shown its application to the citrus. The third chapter offers a comparison and deseription of all these beings. The monsters of the genus citrus have also furnished me an article in this chapter, to which I have added remarks upon the species of India. Finally,' the history of the citrus has been the subject of my fourth chapter. My chief design has been to throw light upon the physiological problems that I have tried to solve. To this end I have sought to determine the different climates in which these species were placed by Nature, and to discover by what degrees and in what manner they were spread, mingled, and naturalized in the countries where we now see them. I have endeavored to spy out the circumstances and causes which ga^e birth to the erowd of varieties, or which have made them disappear.
For the title to my book I have preferred the botanical name of this genus, discarding, as savoring of the fabulous, the term Ifesjterides, so often used by my predecessors. I also use, in the course of this work, the ancient Italian word Ayrumi, which comprehends all the species of this family. It is thought that this word was borrowed by the writers of the sixteenth century, from the Arabs, who called their fruits by a term denoting their acidity. It is certainly a name well ohosen to distinguish this genus. •
A TREATISE ON THE CITRUS FAMILY.
BY M. GEORGE GALLESIO, *
Auditor of the State Council, and Sub-Prefect of Savonu.
TIIEOltY Of VEGETABLE HEPKODUCTIO^.
Ajjt. I.—Of the Citrus—Of its specics—The intermediate races whicJi unite them—The researehcs coneerning the formation of new plants—Tfie diseovery of hybrids—The uneertainty respecting the nature of varicties. The Citrus proper has been for a long time the only species of Agrumes known to Europeans, and has thus furnished botanists the name of the genus to which they have referred all the species, and consequently the varieties also with which our gardens have progressively been enriched.
But among all these different races there have always been distinguished four, whose physiognomy is so marked, and whose characteristics so distinct, that it is impossible to regard them as other than the principal species into which the genus is naturally divided.
The first is the Citron, which has preserved the generic name of Citrus.
The second species is the Lemon, wrongly called Citrus medico, but properly Citrus limon.
The third and the fourth are commonly known as the Sweet and Sour (Bigarade) orange, and have been united by botanists under the common name of Citrus auraniium.
These four species have been almost infinitely multiplied by a chain of varieties, and have been crossed and confounded in such a manner that at the present time they are so united one to the other by an insensible and continuous gradation that it is very difficult to distinguish them. They arc also multiplied in appearance more than in reality by the different names which these varieties have received from the botanists of different countries, as well as by the disappearance of several varieties once known, and the formation of several new ones.
In the midst of this confusion, which would very naturally exist as to the varieties, they should nevertheless have agreed concerning the species, which has always presented characteristics not to be mistaken."
But botanists have never occupied themselves carefully with these secondary divisions, and satisfied with having classified the numerous genera of vegetables, they have regarded the different races sometimes as species and sometimes as varieties, without even determining the characteristics by which natnre has distinguished these two analagous but different classes of the vegetable kingdom.
They long disputed d> ascertain whether the
earth has produced new species of plants since the creation, or whether all which now exist were created at the beginning of the world.
This question, discussed with so much erudition and sagacity, appears to have been decided since we have discovered the secret of the combination of the species by means of the fructifying pollen which passes from one plant to the others; and it is no longer doubtful that nature, rich in her productions, has arranged a kind of marriage between plants differing a little, from which it results that a new plant is produced, distinguished by the name of hybrid.
The discovery of these vegetable mules, which form in nature a class not originally existing, has thrown much light upon and infinitely facilitated the classification of species.
But it still remains to determine the nature and discover the origin of the third race of vegetables, which cannotbe ranked among the hybrids because they belong only to one species, but are nevertheless so different from each other and from the primitive type that we must regard them as distinct beings, having their own peculiar characteristics.
It b principally upon these numerous races, known under the name of varieties, that the opinion of botanists and cultivators is still divided. The hypotheses hitherto formed concerning their nature and formation are so vague and unsatisfactory that it is important for science that light be thrown upon this mystery, and that an explanation of it be given more in harmony with the principles of vegetable physiology. We will begin by examining the opmions held upon this subject.
Aht. II.—Opinions of botanists and agriculturists respecting the origin and cause of varictics and monsters.
When we regard the variety always reappearing in the productions of the vegetable kingdom, and observe the innumerable multitude of new beings by which the surface of the globe is continually enriched, w'e are tempted to believe that nature has abandoned to a number of external agents, cither natural or artificial, the power of modifying her productions and infmitely varying them.
But when we study vegetable life, and examine closely all its changes and mysterious reproductions, we arc persuaded that nature, always regular in her operations, always grand in her results, has abandoned nothing to chance, and that she has determined from the moment of creation all the details of existence, and cast inflexibly the mold in which all beings must ho modeled.
This great truth, which cannot be bidden from the view of the careful observer, nevertheless seems to be with difficulty reconciled with a number of phenomena which are every day presented to view.
On the other hand, we are reassured in these principles by the example of all the primitive species of plants, which are always met with on the earth in the same form under which they have existed for many centuries; we are convinced of this fact, by Lhc bringing together and comparison of those remains of plants found in excavations, and . by the models which have been transmitted to us by painting, sculpture, or descriptions of the ancients.
On the other hand, we know not to what should bo attributed all those uew species or varieties, of which, it seems, our ancestors had no idea, and still more those sub-varieties and those tnonsters which are daily developed under our own eyes, cither by tho seed, or some chance, of which we as yet know not the principle.
It is already half a century since we succeeded in establishing order in the multitude of theso new races, which have been divided into two classes. The first is lhc hybrids; the second, the varietics.
Linnrcus has wrung from nature the secret of the formation of the first; it remains to seek the principles according to which the second arc produced.
I will call the hybrids by the name of the species entering into their formatiou, because it seems to me that every individual which deviates partially from the characteristics of its type, and participates iu the properties of another species, is something more than a variety, and I will reserve this last name for those new plants whose secondary characteristics are modified by any cause whatever without departing from tho species.
Without this Uistinctiou i would be embarrassed in determining, for example, to what species, in quality or variety, the hermaphrodite orange belongs (Citj'us aurantium indicum limocUratum folio ct fntelu mixto), which partakes of the lemon, the orange, and tho citron, and it would necessarily follow that this pretended variety would be found ranked in the same hue as the blood red orange lTec(Citru!j^urantiumsineute kicrochunticum fructu sanguineo) which has only the characteristics of the single orange of which it is a variety
I will not stop to trace the theory of tho hybrids. This system is already so well known that I can add nothins to its development. I shall occupy myself in seeking tho causo of the formation ot vareties, and will present my theory as the result ' f mnny experiments and much observation, which I invite botanists to repeat iu order better to determine their phenomena and their consequences.
In all times it has been observed with astonishment that nature appears moro inclined to give us wild than tine varieties. It is rare that a choice fruit is reproduced from the seed; and we see, for example, that the seed of the most delicate butter pear regularly gives us only wild fruit, whose nrrid fruit, without juice, in nn way
resembles the species from which it is descended.
Even when chance procures us somo fee variety, it is nevertheless not always equal to the fruit that has produced it, and as this chance seldom occurs, and as it is very difficult to establish such recurrence, because it is not foreseen, and because it has fallen but little under the eyes »f enlightened cultivators, it has generally been believed that these varieties are due only to the gralt, to cultivating, or to the climate. Sometimes, indeed, botanists have allowed themselves to be imposed upon by superficial and deceitful gardeners, who, seeing themselves the possessors of several of these new species without knowing their origin, have imagmed and believed that some marvellous operation has taken place, and supposed them duo to grafts, which existed not in nature, and which would not give such a result if they did exist. Hence tho different agricultural systems which have reigned for several centuries, and of which a part reigns still to-day, even among enlightened agriculturists.
There are, for instance, few cultivators who arc not convinced that the sour orange is the type of the species, and that all seed from an orange tree, even though it be a sweet one, gives only sour orange trees. This pretended phenomenon, which has been believed on the faith of the cultivators, without ever being determined by exact experiments, has been generalized respecting almost all fruit-bearing plants; and it has been established, as was supposed, iu principle, that the wild fruit was the type of the species, and that flue fruits, being only individuals improved by art, could produco by their seeds only the type of which they arc the conservators, or, in other words, individuals in a state of nature known under the name of wild plants.
Other agriculturists have imagined that tho seed of the sweet orange produced sour or bitter orange trees only when takeu from a graft of the sweet oraugo placed upon the sour orange tree, aud this system has been extended to the other species of fruit, such as the apple, peach, pear, and other trees. They have, perhaps, beou forced to this modification iu tho theory of artificial improvement by the example of some individuals of choice fruit which they have seen to be produced from the seed, and as they could not conceal the truth of these accidents, aud as thoy saw, moreover, that such a case but rarely occurred, they imagined that those fruits which reproduced without degeneration when taken from a seedling, lost that property whenever they were taken from a graft on a wild tree; and they even deluded themselves so fur as to believe that the pericarp followed the nature of the graft, while the seed followed tho nature of the tree receiving the graft.
All these prejudices have prevented cultivators from adopting tho method of multiplication offered by nature, and, persuaded that the seed could give only a wild pruduct, they have condemned all seedlings to be grafted.
But these artificial methods only preserved the species already acquired. They multiplied the individuals but never renewed the race, and consequently it st ill remains to be discovered in what manner those varieties were obtained, which they could not deny were unknown to our ancestor;. In order to ftatinfv this natural inqnic