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plants wilh single flowers. This experiment was continued in the following manner: I chose plants of semi-tlouble flowers. and fecundated them with the pollen of other semi-double flowers. Several others of semi-double flowers were left untouched. The seeds from the fecundated flowers produced roots bearing for the most part double flowers, crowned often in the middle by a tuft of green leaves which rendered them very pretty. "The seed from the flowers not fecundated, although already semi-double, gave only plants bearing single flowers. I repeated this experiment for several years, but always with the same result, and a similar experience with other flowers gave also the same.

Experiment VI.—I fecundated the flowers of the orange with the pollen of the lemon tree, and I obtained a fruit whose skin was cut from end to end by a stripe yellow and elevated, having the characteristics of the lemon. The taste of the fruit was entirely that of the orange. It had few seeds, and these small and poor.

Experiment VII.—I fecundated tho flowers of an orange tree with the pollen from several other orange trees, and obtained several times fruit whose pericarp had an irregular form, containing few seeds and those very defective.

Experiment VIII.—I sowed orange seeds whose flowers had been fecundated, and whose pericarp had suffered no change; and obtained plants which do not yet bear fruit, but one of them is devoid of spines, and another displays a very vigorous foliage, which distinguishes it from ordinary orango trees.

METHOD PURSUED IN ARTIFICIAL FECUNDATION.

The procedure which was employed in the artificial fecundation is simple, and indicated by nature herself.

I chose the ripest and most highly colored pollen from the most thrifty flowers, and those most nearly ready to bloom, and applied it to the pistil of the flower which I wished to fecundate. In order to render the operation more exact, I detached the flower from its stem, and having despoiled it of corolla, I rubbed the anthers without touching them, upon the stigma to be fructified. This operation was repeated with several different flowers, without depriving the flower submitted to the operation of its stamens. I took care to repeat it several times each day for several days. This precantion was necessary in order not to miss the moment of Tilooming in the pistil which was to receive the pollen, and to assure myself by moans of a quantity of this pollen taken from different flowers, respecting its disposition to exercise its fecundating qualities.

In the flowers of the orange tree the moment of maturity for fecundation seems to be announced by the nppearance of a honey-like drop which forms on the stigma of the pistil.and serves to retain tho dust applied to it; ami the same maturity in the pollen is indicated by the deep yellow color it then assumes, and by its quality of adhering to the finger when touched; but it is also necessary to be careful to multiply the experiments, becanse often after having fecundated several flowers as oue may suppose, none, or but few, may be successfully operated upon. But success is more certain with Hie ranunculus and carnation.

CONSEQUENCCS.

Cuimequcucc I.—Mixed fecundation operates in various ways upon vegetables. It may act upon tho ovaries or upon the ovules. (Exp. V., VI., VII., and VIII.) When it acts upon the ovaries the pericarp of the fruit which has been fecundated receives modifications, and bears but few if any seeds. (Exp. VI. and VII.) When the action is upon tho ovules the fruit which encloses them docs not seem affected by it, bat these ovules grown into seeds give some trees which do not resemble the parent tree, and most frequently have a tendency to sterility.

This tendency to sterility determines itself in different ways; sometimes upon the flower, when wc have plants with double, or semi-double, or possibly with simple and sterile flowers; sometimes upon the fruit, when wc have plants with sterile or semi-sterile fruit, for these fruits cither bear no seeds, or very few, and those badly nourished. In all cases these species of mules or hybrids show unusual vigor in the thrifty branches freo from spines, or in the better nourished leaf, or the flower with multiplied petals, or the fruit of more beautiful pericarp. These characteristics especially distinguish the greater part of the beantiful varieties; hence the varieties are due only to an extraordinary fecundation which acts upon the seeds and modifies them at the moment of their conception.

Art. VIII.—Phenomena observed in hybrid plants.

Observation I.—There is a species of Citrus known in Italy by the name of bizzaria, and in France by that of the hermaphrodite orange (aurantium limo citrahimJ'olio etfructo mixta), and which bears at the same time sour oranges, lemons, citrons, and mixed fruits.

I have observed upon this hybrid that the same branch bears at the same time leaves and flowers, of which some announce the sour orange tree, others tho lemon, and still others the citron tree. They produce fruit which belong sometimes to one of these specios, at other times to two or even three of them mixed.

A scion which springs up violet often develops a branch, some of whose flowers are violet, others white, and the buds of this branch grafted upon another stock sometimes produce there the caprices of the variety, and sometimes perpetuate a simple sour orange, although they may have been taken from tho axil of a citron leal; and reciprocally a simple citron, though taken from the axil of a sour orange leaf.

This caprice has forced the gardeners to multiply it by the layer. It is thus that this hybrid is perpetuated without degenerating.

Obsenation II—I fecundated white pinks with red pinks reciprocnily The seeds thus produced gave pinks of mixed flower. Several of these plants presented the following phenomena: The same plant which gave mixed flowers gave some flowers entirely white, and others entirely red. One 3'car it gave only red flowers, and the next mixed flowers again. Others, after having produced mixed flowers two or three years, siibscquently produced only red ones; they seemed entirely to have returned to the species.

Observation 111.—Simitar to the bizarreric is the violet sour orange, which is cultivated at Paris, (citrus aurantiwn indicum fructu violaces). I havo noticed in the specimen growing in the Jardin des Plantcs that of the flowers springing from the same branch—some were white, like those of the orange tree, and others violet, like thoso of the lemon tree—a variation appearing equally in the fruit . Others have observed in individuals of this race that this caprice may appear one year, be wanting the second, and reappear the third year.

Observation IV.—With the pinks, of which I spoke above, may be compared the streaked orange trees (citrus aurantium folio et fructu variegate). I have seen some of them which developed branches in no way affected by that yellowish border which marks the foliage of these trees; and I have seen this caprice reappear.in others after it had been almost lost for years.

Observation V.— The gardeners of Liguria have a practice of separating from other cabbages the cauliflower, destined lor seed, by transporting them into isolated gardens, anjj surrounding them by a sort of enclosure of branches or straw in order to preserve them from the influence of the other species.

Owing to this precaution vegetable gardens present only plants of the ordinary form.

I have seen plots of cauliflowers (brassica oleracea botrytis) and ofbrocolis (brassica vulgaris sativa), whose seeds had been gathered from plants of these two species, which had been sown pell-mell in the same bed, and almost every head had curled and streaked leaves.

CONSEQUENCES.

The pollen of one species acting upon the ovary of another, produces a modification in the seed which results from it. This modification is sometimes uniform and constant, and sometimes variable and inconstant.

It offers most frequently the example of a mixture in the substance of the germ, which is identified with it and affects all its parts without undergoing afterward any change.

It offers sometimes the example of a principle which circulates in the essence of the vegetable and sometimes affects its products, and which sometimes, without affecting them externally, passes, nevertheless, into their essences, to reappear in succeeding products, as well as sometimes abandoning one part of the vegetable to concentrate itself in another. These caprices appear in hybrids but not in varieties. In these last the principles which arc blended have among them considerable analogy, while those united in the hybrid are by nature heterogeneous.

The hermaphrodite orange is due to the seed. This is an ascertained fact, established in a dissertation by a Florentine naturalist, published 'in 1644.

It is owing to fecundation; it is a fact which results from its forms, from the nature of its productions, and from all the phenomena of its existence.

The pink of mixed flowers, giving red and white flowers, is due to the seed, and to a seed proceeding from a fecundated flower; it is a physical tact, since it results from an operation made with the greatest exactness.

The phenomena of these two hybrids have a

great analogy with the phenomena of the streaked plants.

We remark in these hybrids this same inconstancy in the accidents which gave rise to the belief that the streak iis only a disease. If the heterogeneous mixture in fecundation Is the cause of the mixture which affects tho fruit of the bizarreric and of the colors which appear and disappear in the pink, it may be equally the canse of the streak. The streak offers no other circumstance which it might be difficult to reconcile with these principles except the inconstancy of its phenomena. The example of the orange and the pink prove that it is not incompatible with this canse. If this streak be a disease, it originates in the germ and affects the substance of it in the fructifying principle, and in this case can be due only to fecundation. But this phenomenon of streaks seems to be rather a monstrosity than a malady, since it has uniform and regular forms which affect all the leaves alike. If it were7 a malady, the individuals affected by it would not possess the vigor and health which usually characterize them. It would not be produced by preference- from seeds gathered from plants mixed with other varieties, and a whole plot would not be affected by it, as happens in the canliflower, but they would appear isolated among healthy individuals, and might be produced by any seed whatever.

Aivr. IX.—TluMries respecting vegetable reproductionCorollaricsConelusion. These experiments, facts, and analogies, taken as a whole, necessarily give rise to principles which form so many theories in the system of vegetable reproduction.

1. Nature has created the genera which form so many families distinguished from each other by peculiar marks.

2. Nature has created the species also which form so many branches in these families to which they belong on account of common characteristics.

3. The mixture of these species in the union of the sexes has given rise to hybrids.

4. The mixture and proportion of the productive principles of several individuals of the same species have produced the varieties.

,>. The irregular and forced action of one principle upon the other in the act of fecundation, either in the same or in different species, has given rise to monstrosities.

6. The varieties are, therefore, due only to tho seed.

7. The seed originates equally the varieties called choice and those growing wild.

8. Cultivation has destined tne first to furnish the graft and the second to bear it.

9. The graft and the slip only can perpetuate these varieties in their natural condition.

10. The seeds of these varieties are also submitted to the influence of fecundation and subject to give new varieties by it, sometimes better, sometimes inferior, in quality. It gives types when the fecundation takes place according to the laws of nature'.

11. Monstrosities arc individuals whose organization has undergone an alteration by the fact of fecundation.

12. If this alteration occurs in the ovary the

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monstrosity is in the fruit which results irbm it and perishes with it. If this alteration be in the ovules, the monstrosity is in the germ, and this germ sown produces a variety which bears only monsters.

13. Every monstrosity regularly is sterile, either from the nature of the flowers which are without sex, or whose sexual parts become petals, or by the nature of the fruit which has no seeds. It must be multiplied by the graft or slip.

Corollary I.—The species form many branches in the families known as genera and to which they belong by common ties or characteristics; these are distinguished from each other by pecu- I liar marks or features. .

These features or characteristics are constant, | and distinguish the type from the varieties. The | types are always fruitful. They are reproduced by their seeds unless these seeds are modified by fecundation. They are also reproduced by the seeds of the varieties.

Thus the seed-beds offer the surest means of distinguishing the species from the varieties.

Every tree which is perpetuated by descent and preserves its forms, characteristics, and properties is a type. It can undergo no changes except by fecundation; but those changes which are made in the g_erm do not extend to the reproductive principle. The sexes disappear in these individuals, or pass intact througli the modifications of the flowers and the ovary. They bear in them the principles of the type. Among peaches I have verified three types, the peach, the clinkstone, and the nectarine peach. Among cherries I have verified two, the white-heart cherry, and the round or black cherry. 1 have data which leads me to suspect that there is a third type.

I have not yet determined the types of the apricot, the apple, or the pear. My experiences are not yet sufficiently advanced respecting these species. I have, however, determined to a certainty that the Citrus has but four species.

CoroUary //.—The blending of species in the reunion of the sexes has given rise to hybrids.

The hybrid partakes of the characteristics of the two species of which it is composed. Thus its exterior physiognomy reveals its origin. It has a tendency to sterility. The hybrid presents phenomena which are very singular. The mixture sometimes affects the substance of the vegetable, and we have then a mixed fruit whose forms are constant, but which is generally unfruitful. Such are the poncire, the double mixed pink, and the double flowered ranunculus. At other times the mixture seems to be, as it were, wandering in the vegetable, and then it affects isolated parts of the plant capriciously, and disappears sometimes, to reappear in the products even of those parts which did not seem before to be affected. Such are the orange, de bizarrerie, the violet orange, and the variable-flowered pink. ] In these cases the fruits affected are sterile, or semi-sterile, and the fruits not affected produce seeds.

CoroUary III.Varictics.—The mixture and proportion of the reproductive principles of sevcral'individuals of the same species have given rise to varieties. Varieties are only aberrations or departures from the type. They are of two sorts: Varieties from excess, aud varieties from

deficiency. Varieties from excess are due to a superabundance of the masculine part, and still more to the mixture of the pollen of several flowers. Varieties from deficiency are due to the lack of proportion between the sexes, or the weakness of the masculine part. They are also sometimes due to a defective organization of the ovary. Varieties from excess most frequently tend to sterility. They are marked by a striking thrift and a lack of thorns. Their seeds, when they have any, reproduce the type, unless a foreign fecundation has acted upon the flower and formed a new combination.

Thus, every sterile or semi-sterile fruit is only a variety. Its seed, in the state of nature, will return to the species. It is, therefore, by means of the seed-bed that we are enabled to recognize the species to which varieties belong. Stoutness and the loss of (horns always accompany the absence of seeds. It is, therefore, at the expense of the generative parts that vegetables acquire marked development in the leaf, bud, or fruit. Nature seems to have assimilated them to animals which acquire volume and lose the hair when they are barren. Varieties from deficiency deviate from the type for reasons directly opposite to those which cause deviation in varieties from excess. The imperfection of the fecundation affects the germs which bear in their principles a defect of organization. These germs produce only wild plants, as we call them, which are degenerated individuals, whose products are badly organized, and whose seeds are poorly nourished. These seeds, which often perish, still ordinarily generate feeble and languishing plants, but sometimes they give types.

It is to the accidental vigor of a branch bearing well-formed flowers that we owe this return to the species. Thus, varieties by deficiency are due often to climate and culture, but these influences act only indirectly. They facilitate or retard the development of individuals, and, consequently, the perfection of the reproductive principles; but every change is operated in the germ and only as the effect of fecundation.

Every variety is a monster to nature, and some varieties are so regarded by men, such as the varieties from deficiency. But varieties from excess ordinarily form the delight of the table and the ornament of the garden. Nature aims at only the production of seed, and when fruit bears many seeds, it is perfect in the system of Nature.

Man seeks only pleasure in Nature, and hence judges differently of vegetable productions, on account of the advantage to be derived from their use. He, therefore, prefers, in certain fruits, those varieties whose pericarp is more developed, tender, and juicy. He is thus opposed to Nature, as in the case of the apple, pear, and peach. In other fruits he prizes the cotyledons or seeds, and regards the pericarp as useless, the more so in proportion to its development; aud in this be approaches the plan of Nature, as in the almond, chestnut, the bean, and the pea.

Others still are prized for a portion of the pericarp, and a variety is considered choice only when this part is developed at the expense of» the pulp, as in the melon and citron. Other fruits are valued for the pulp only, as the lemon and orange. There are also vegetables in which the flower alone is esteemed, and then that va

riety has the preference in which this part is developed at the expense of the generative parts, as in double and sterile flowers.

Others are sought only for their aroma, as the sour orange. Finally, capricious man attaches value to monsters even, which are useless to him, and seeks for ornament odd and rare forms, such as shriveled leaves, leaves developing out of proportion the yellow streak which borders the leaf, a tendency of the branches to descend to the soil, and other monstrosities of this nature. All these caprices form the ornament of our gardens and the delight of our tables: but to Nature they are departures from the object she has proposed to herself. She repels them and condemns them to perish. But man has succeeded in preserving and multiplying them. The seed refusing to give gerras capable of reproducing them, he has propagated the individual he possesses by dividing it into a thousand parts, and thus by grafts and scions preserves it without change. Thus these adulterous sons have filled our gardens, and the types have been banished to the woods.

MONSTERS.

According to the fifth theory monsters arc only individuals whose organization has undergone alteration by fecundation. If this alteration take place in the ovules the monster is in the germ, and this germ sown, produces a variety bearing only monsters. We have already analyzed this phenomenon. If this alteration take place in the ovary, the monster is in the fruit which results from it and perishes with it. This phenomenon is so extraordinary that I hesitated a long time to believe it, but the experiments which I made respecting it have convinced me of the truth of its existence.

It presents three kinds of facts. The first is the alteration of the forms of the ovary. This part acquires a partial and irregular growth, which develops the pericarp on one side, and impresses upon it very singular forms, such as linear, depressed or curved prolongations, which often contain in iheir interior a pulpy principle or a unilocular pulp. This phenomenon often appears in the orange and lemon. I have sometimes seen it in peaches.

The second fact is the change of nature in a part of the ovary or of the pericarp resulting from it. This exterior body sometimes bears a binding or stripe of the species with which it has been fecundated, as the orange, whose flower has been fecundated by the pollen of the lemon. It is difficult to harmonize such phenomena with principles well understood; but a fact is u fact, and Nature is sometimes as impenetrable as marvellous in her operations.

The third fact is: One flower fecundated by a quantity of dust from several other flowers offers the phenomenon of a fruit containing in itself a second fruit of the same nature. This phenomenon is frequent in oranges. Rumphius says that at Amboine there are species which present many such instances, but cease to give them if transplanted to Banda. This has always been attributed to fecundation, and my experience goes to confirm this opinion. The fruit which presents this appearance is often ruffled, or in a manner folded inwards; at other times the ruffling resembles a second fruit which proceeds from the interior of the first, but always ruffled in form. If

wc cut these fruits we perceive a mixture of peel and cells, the one in the other, which creates confusion and announces superfetation.

These monsters rarely bear seeds. They frequently occur in certain species, are rare in others, and never appear in the larger part of our indigenous vegetables.

These differences are due, perhaps, to the different dispositions of the sexual organs and their relative conformation. They are, perhaps, due to difference in climate, which may favor or injure them at the time of flowering, and to other circumstances which Nature conceals from the eyes and researches of man.

CHAPTER II.

TUB GENUS CITRUS ARRANGED ACCORDING TO THE NEW THEORY OF VEGETABLE REPRODUCTION.

Art. I.—The CitrusDivisions of Botanists and AgriculturistsDivision's adopted in this workPrimitive specicsThe specks of the Indics. The Citrus is a genus whose species arc greatly disposed to blend together, and whose flower shows great facility for receiving extraordinary fecundation; it hence offers an mfinite number of different races which ornament our gardens, and whose vague aud indefinite names fill the catalogues.

It is the multitude of tllese beings which we propose to describe. We shall endeavor to classify them according to the principles already explained. We shall describe species, hybrids, and varieties, and endeavor to establish their identity. This is, perhaps, one of the most difficult portions ,of our work, first, because the botanists or agriculturists who have described the varieties have not always done so with the exactness requisite to enable us to recognize them among so many different names; and, secondly, because in the course of centuries several of these varieties have disappeared, from frosts or other influences, and been replaced by a quantity of new varieties which resemble them, and which, by means of some slight differences, create confusion in the application and comparison of these descriptions.

It is only with the aid of knowledge which I have acquired of these varieties in our gardens, where I have cultivated them for a long time passionately, and in those of several semi-tropical countries which I have visited for this purpose, that I venture to undertake the task of reconciling this numerous and perplexing nomenclature.

I will begin by examining the species.

Some authors have regarded the citron alone as the original species and the type of the other species.

Tournefort, with most botanists of the sixteenth and seventeenth centuries, has recognized in the lemon and sour orange the characteristics of types as well as in the citron, and has considered the sweet orange as a varietyNc the sour orange.

The Arab agriculturists have ranked Adam's apple (la pomme d'Adam) among the species, which they have designated by the name of lay

aatuuu or zauibau; and being acquainted with the; sweet orange only, they divided the genus into , the citron, lemon, sour orange, and zambau.

The Italian and French agriculturists have added to these four species the sweet orange and a multitude of varieties known by the names of limes, lumics, poucires, &c.

Linnaeus, attached to the artificial system which he had just established, placed the Citrus among the polyadelphias, referring to the union of the stamens in several bundles; and he ranged it in the order of icosandrias, referring to the number of organs which he supposed, in all the species, to be twenty, although we find in the lemon and citron as many as thirty or forty.

He also fixes the accidents which determine the form of the petiole of the leaf, and not having remarked that the petiole of the citron tree is not articulated like that of the lemon, he has made of these two races a single species, distinguished by the characteristics of linear petioles (petiolis linearibu*.)

The winged form of the petiole has been the characteristic which has determined his second species, and as this accident distinguishes equally the sweet and sour orange, Linna;us has regarded the latter as the type and the former as a variety, and united them under the name of Otirus petiolis alatis, or Citrus, with winged petioles. Finally, he has made a third species of a Japan orange, described by Krempfcr, referring to the ternate leaves, and called it Citrus trifoliata.

The later editors of Linnieus augmented the number of these species by one called Citrut decumana, which Linnreus himself ranked among the varieties. They thought that its obtuse and scolloped leaf (foliis obtusis emarginatis) was a sufficient characteristic to constitute it a type, and did not observe that this peculiarity is neither general nor constant, and that in consequence it is rather a monster than a characteristic feature. They have also added the Citrus angulnta or limoneUus angulomts of Rhumphius, and the Citrus japonica of Thumberg, whose characteristics are, without doubt, too different from those of our specimens of the Cjtrus family not to constitute distinct species.

We have followed a new method; we have begun by seeking the species among all European specimens of the Citrus, and arranged around these their hybrids and varieties.

We have also presented some reflections upon the species of the Indies, of which we have given only an idea, leaving to more enlightened botanists the task of examining and classifying them, as we have those of Europe.

The seed-beds.have been the principal means made use of in our search for species.

We have seen the citron tree of the Jews (Citrus medico, cedrafructu oblongo crasso eduliodoratissimo, Gall. Syn.,) reproduced constantly from the seed. It has many seeds, the greater part of which always give citron trees having constantly the same characteristics in aspect, form, and properties; iU»j therefore, a type.

All otfier citrons are sterile or nearly so, and hence are only hybrids or varieties. Such are the Chinese citron, (Citrus medico, cedra fructu 'maximo aurantiato, Gall. Syn.,) the cedrat of Florence, (Citrus medico eedra Flnrentina fructu

: parro. Gall. Syn.,) and several others which rc\ scmblc them.

The common lemon (Citrus medico linion fructu ocato, G. !'>.,) also contains many seeds. It is reproduced constantly from the seed, and its peculiarities are perpetuated in its descendants. It is, therefore, a species. It produces hybrids and varieties, but they are found rarely, and only among many types. They have few seeds, and these reproduce most frequently the type. Sometimes they contain no seeds, and it is always in those deviating most from the type that we remark this sterility. The poncire of cedrat lemon (Citrus *>nedica limon fructu ciirato, Gai.l. Syn.,) is of this number. v

The sour orange also produces many seeds, which always reproduce sour orange trees. Hybrids are met with only among a great number "of types. Varieties are found more frequently, but these deviate very little from the characteristics of the type, and their seeds always reproduce it; hence the sour orange is a species.

The sweet orange has many seeds, which always reproduce sweet oranges. They give rise to varieties, and we often remark in the same sowing, orange trees of ordinary fruit and others of superior fruit, but there is no single example in which these seeds have produced a sour orange tree. The sweet orange is, therefore, a species.

When it gives monsters they have no seeds, or very few; such are the seedless orange (aurantium semine carens, Feb.,) the red orange (aurantium hicroehunticum, Gall. Syn.,) and the small China orange (Citrus aurantium couk et fructu, pumilo, Gall. Syn.)

These four species are, therefore, certainly types. They do not, perhaps, present all the exterior characteristics which the botanists have, adopted to distinguish species; but in the study of natural history it is necessary to guard against forcing nature in order to make her conform to various systems.

Bhe is not confined to constant forms and determinate modification in order to distinguish vegetables. She is pleased to vary those distinctive signs by which she has marked these divissions. She has, from preference, fixed them iu the fructifying parts and the form of the leaf, but has not, on this account, renounced less general peculiarities. It is sufficient that a characteristic be constant, or unalterable, or pronounced, in order to be distinctive for nature. Thus the acidity and bitterness of the pulp of the sour orange, the aroma of its peel, its leaf and flower, being qualities constantly attached to this plant, altered neither by culture nor climate, nor even by the seed, may and must be distinctive characteristics of this species.

These are the pnnciples which have guided us in the classification of the species of the Citrus of Europe. We have been able to recognize only four of them; all the others arc only hybrids or varieties. They all present the mixture of these four mother-species, and their characteristics, confounded and combined in a hundred different ways, never depart from the model of these four types.

Such is evidently the nature of all the races seen in the gardens of Europe. It is only in the Indies that we meet with a great number of others whose physiognomy assimilates them to our

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