ee 4 105 172 357 @& NEW SERIES. VOLUME I. JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. I. On Hybridism considered as a‘cause of variability in Vegetables. By M. Cu. Navpin*. Tue changes of form in the species of the vegetable kingdom are very properly considered at the present moment one of the phe- nomena which are most worthy of attracting the attention of observers. The subject of the variability of species, which was put aside amongst questions of secondary consideration, has within a short time assumed an unexpected importance; and without mentioning the philosophical deductions to which it has given rise, it may be asserted that it forces itself on our notice at the very commencement of all our descriptive works. For the last ten years I have devoted to it all my attention, and though duly estimating the facts in this direction observed by my predecessors, it is nevertheless to my own experiments I have looked especially for enlightenment on this obscure subject. I do not pretend to have solved all the difficulties which it involves, but I think that I have arrived at results which, I hope at least, will throw some light upon points in the biology of vegetables which have been hitherto perplexed. In a memoir which I had the honour of presenting to the Academy two years ago I established this fact, confirmed since by new experiments, that, setting out from the second generation, hybrid vegetables, when they are fertile, revert very frequently to one of the two species from whence they were derived. This * Translated, by permission of the author, from Comptes Rendus de l’ Académie des Sciences, Nov. 21, 1864. VOL. I. B 2 ROYAL HORTICULTURAL SOCIETY. reversion to forms authorized by nature is not universal ; nothing is more common, in fact, than to find in hybrids of the same . origin and of the second generation, or of a generation more advanced, in company with individuals which revert to the form of the parent species, a more or less numerous residue of indivi- duals, which do not retrograde, or which even differ more from these last, than they differ from hybrids of the first generation. What sort of physiognomy do these refractory hybrids present, and what are their descendants? ‘This is the question which I purpose to examine in the present memoir. In 1862 I made numerous crosses, all of them successful, be- tween Datura levis, ferox, Stramonium, and quercifolia, four species perfectly distinct, between which there are no known interme- diates, and which moreover do not appear susceptible of variation. Nevertheless, though very distinct, these species are sufficiently closely related to admit of reciprocal impregnation, and to give rise to hybrids, which, though sterile at first, become very fertile at a more advanced period. They were then in the most favour- able condition for the object which I proposed—the observation of their hybrids during at least two consecutive generations. In order to apprehend properly the facts which follow, I ought to state that the species of Datura of the subgeneric group to which these four species belong, may be divided into two groups, one in which the plants have green stems and white flowers, the other in which the stems are more or less brown, or blackish purple, and the flowers violet. For brevity I shall call them the white and violet groups. -D. Stramoniwn, levis, and ferox belong to the first; D. Zatula, quercifolia, and some others to the second. As I have just remarked, I have made numerous crosses be- tween these species, all‘of which have succeeded, and under such conditions of insolation that I could have no doubt of the results which I obtained. I will not speak here of all these experiments, which I reserve for a more extended memoir; I wish only at pre- sent to lay before the Academy the very remarkable phenomena of variation which have been elicited by these crosses, and to point out the consequences which appear to me to result from them. Datura levis and ferox, the two species which differ the most in the white group, having been fecundated the one: by the other, and in both directions, I was able in 1863, by help of the seeds derived from this double intercrossing, to raise sixty individuals of Datura levi-ferox, and seventy of D. feroci-levis, in all 180 hybrid plants, derived from the same parents, which had alter- NAUDIN—ON HYBRIDISM. = nately acted the part of father and mother. All these plants attained the most complete development, and were so perfectly like each other that the two sets might easily have been regarded as one. This is a new confirmation of what I have already announced in the memoir cited above—that there is not a sensible difference between reciprocal hybrids of two species, and that in the first generation the hybrids of the same origin resemble each other as much as the individuals of pure species from the same sowing. In this first generation, I repeat, the entire collec- tion of hybrid individuals of the same origin, however numerous they may be, is as homogeneous and as uniform as a group of in- dividuals of an invariable species, or of a pure and neatly-defined race would be. But these 130 hybrids presented a fact which was quite new to me: if they perfectly resembled each other, they differed strangely from the two species from which they were derived. They had neither the stature, the habit, the flowers, nor the fruit of their parents; there was not even anything intermediate between their forms which were so weil known and so decided. Any one who did not know the origin of these hybrids, would not have hesi- tated to make a new species of them, and what is worth notice, would have classed them in the violet series, for all had the flowers of this colour and brown stems. Notwithstanding, as I said above, the two parent species belong to the group charac- terized by green stems and white flowers. In the face of this unexpected result, one might have been tempted to believe that two species, intermarrying, might impart to their progeny characters which they do not possess themselves ; but such a conclusion was too paradoxical to be accepted without a reexamination. I resolved therefore to recommence the experi- ment the following year, observing at the same time more closely not only the hybrids, but also the species from whence they were derived. | This year (1864) I have sown afresh D. levi-ferox and feroci- levis, and by their side D. ferox and D. levis in a state of purity. Thirty-six new plants of D. levi-ferox, and thirty-nine of feroci- levis reproduced all the identical features of their brethren of the preceding year. They had the same brown stems, the violet flowers, and thorny fruit. But what I had not previously re- marked, in D. ferox of a pure strain the stem at the moment of germination is of a deep purplish violet. ‘This vivid tint extends from the root to the cotyledons, where it suddenly ceases, giving B2 4 ROYAL HORTICULTURAL SOCIETY. place to the clear green tint; but it remains during the whole existence of the plant on the part which it occupies, and where it traces a coloured circle. From this moment all was clear: if the hybrids of D. ferow, allied to another species of the white group, have brown stems and violet blossoms, it is because D. ferow itself possesses the germ of this colouring. In the pure species, the colouring remains in a rudimentary state, occupying only the small interval which extends from the commencement of the root to the cotyledons; in the hybrid it acquires an enormous increase, extending over all parts of the plant, and manifesting more espe- cially its action on the flower. Here then is a first mode of varia- tion induced by the crossing of two species, and which produces its effects on the first hybrid generation. The second generation is about to offer us variations of another kind, and still more remarkable. All these hybrids, though sterile at the first seven or eight dichotomies, were very fertile in those which were developed later. Their seeds, sown last spring, gave me in the second generation nineteen plants of D. feroci-levis, and twenty-six of levi-ferox. The two sets still resembled each other, but by a cha- racter diametrically opposite to that which was the prominent trait of the preceding generation. The most astonishing diversity of feature succeeded the former great uniformity, a diversity of such an extent, that out of the forty-five plants of which the two sets were composed, no two were found which precisely resembled each other. They differed in stature (in the proportion of one to four), in habit, in the form of the leaves, the colouring of the stem and flowers, the degree of fertility, the size of the fruit, and the degree of aculeation. With the exception of a single indi- vidual of the levi-ferox set, which had completely reverted to D. levis, with this slight difference that there was still at the base of the stem a circle of purplish violet, not one of these plants had sensibly approached this species, and there was only a very small number in which one could recognize faint resemblances to D. ferox; the greater part even more closely resembled D. Stra- monium and D. quercifolia, with which they had no relationship, than the species from which they descended. Some had white flowers and green stems, either self-coloured or tinted with purple at: the base, while others had violet flowers of various shades, and stems more or less brown, sometimes even of a purplish black as deep as that of D. Zatula, which is the most perfect type of the violet group; the fruit was of all sizes, from that of a filbert to NAUDIN—-ON HYBRIDISM, 3) that of a large walnut, and some of them were very spiny, while others were covered with tubercles, or almost destitute of spines ; certain individuals bore fruit at the first fork, while others were fertile only towards the last, and finally there were some which set only a single fruit. On the whole, the forty-five plants of the two sets constituted, so to speak, as many individual varieties, as if, the bond which ought to unite them to the specific types being broken, their vegetation had wandered in every direction. This is what I call irregular variation, in opposition to another very different mode of sporting, of which I shall speak presently. I could bring forward many other examples of the excessive variability which arises in consequence of crossing. Not being able to give to this note all the space which the subject demands, I shall confine myself to the following examples, which have likewise been furnished by my experiments. In 1863 I received from an horticultural amateur a full-grown plant of Mirabilis longifloro-jalapa of the first generation, the issue, as the name implies, of the common Marvel of Peru, with purple flowers, fecundated by JL longiflora. A. seed obtained from the first cross of the two species accompanied the plant, which was destined to give me a second hybrid individual, equally of the first generation. The two plants, cultivated side by side, became enormous. Intermediate in the same degree between the parent species, which they far surpassed in stature, they resem- bled each other as exactly as possible, which might be expected, as they both belonged to the first generation. They were mode- rately fertile, and out of the many thousand flowers which they expanded in the course of nearly three months, they produced some hundreds of perfectly similar seeds. The older of these two plants having already borne fruit the preceding year, and some of its seeds having been sent to me by the donor, I obtained the same year (1863) six other hybrid plants of the second generation. None of them acquired the large stature of the hybrids of the first generation ; none, more- over, resembled them. Of these six plants, there were two which seemed to be the image of each other, so slightly did they differ: this was an exception; they flowered abundantly, but though well developed and very vigorous, they remained entirely sterile. A third almost reverted to the normal form of Mirabilis jalapa, of which it possessed the stature, the leaves, the flowers, and the fer- tility ; it differed only in a slightly more expanded habit, and the tube of the corolla being more elongated. The three last were 6 ROYAL HORTICULTURAL SOCIETY. plants of low stature, more or less deformed, as different from each other as from the hybrids of the first generation; besides, like the two first, they were sterile, or at the most yielded only a few fruits, in which the seeds were only incompletely developed. Three new plants of the second generation, cultivated in 1864, presented the same diversities of physiognomy; they no more resembled those of the former year than the first hybrids. One of these, which approached JZ. yalapa very sensibly, was extremely fertile ; the two others flowered very unequally, and did not yield a single seed. What results from this second experiment is still the irregular variation of the offspring of a hybrid plant, when it does not resume the livery of the species from which it descends. It may be asked whether this propensity of hybrids to vary continues to the third and following generations, when they pre- serve their fertility. My answer to this question is as follows :— I observed in 1863 and 1864 the sixth and seventh generations of a hybrid which I have kept for several years, Linaria purpureo- vulgaris, both represented by some hundreds of individuals. A good number of these last reverted, some completely, the others partially, to the form of Linaria vulgaris with yellow flowers, a small number to those of Linaria purpurea with purple flowers. Others, still very numerous, inclined, so to speak, towards neither the one nor the other, but nevertheless did not resemble the hybrid of the first generation. There were al! possible kinds of variation ; tall or dwarf stature, broad or narrow leaves, the corolla deformed in various ways, discoloured, or exhibiting unusual tints, and out of all these combinations there did not result two indi- viduals which were perfectly alike. It is very clear that we have to do here with irregular variation, which engenders only indivi- dualities, and that uniformity is not established between the de- scendants of hybrids, except on the condition that it resumes the normal livery of the parent species. Similar facts, to which all the attention which they merited has not been paid, have been produced, and are produced daily in the practice of Floral Horticulturists. Here is a well-known and well-authenticated instance: there exist in gardens two species of Petwua pertectly defined, the one (P. nyctaginiflora) has white flowers, the other (P. violacea) has purple flowers, neither of which at present has varied, but intercrossing easily and yielding hybrids as fertile as themselves. In the first generation, all the hybrids are alike ; in the second they vary in the most remarkable degree, some reverting to the white species, others to the purple, and a NAUDIN—ON HYBRIDISM. yf large residue showing all the shades between the two, When these varieties are fecundated artificially by each other, as is the practice of some gardeners, we obtain a third generation still more parti-coloured, and continuing the process we arrive at extreme variations, sometimes at monsters, which the prevailing fashion regards as so many marks of perfection. The essential point is, that these varieties are purely individual, and without any persistence. Their seeds when sown yield new forms, which have no greater resemblance amongst each other than they have to the plants which produced them. Were we to review other groups of ornamental plants, where at the commencement of their cultivation there existed two or more species sufficiently alike in organization to give rise to fertile hybrids, we should discover the same facts of individual, and not collective variability, such as I have just noticed. Primroses and roses, not to bring forward other instances, are memorable ex- amples. Intercrossed a thousand times, either intentionally by horticulturists, or accidentally by insects, the species of these two genera have given birth to varieties so numerous, that we can scarcely reckon them up, and that the primitive types of the species, merged in this confused and ever-changing multitude, have scarcely more than a conventional existence. Whatever the variety may be of rose or of the garden-primrose, so well named Primula variabilis, whose seeds we sow, we may be sure before- hand that it will not be identically reproduced, and that we shall see almost as many new variations as individuals spring up from the seed. This leads me naturally to glance at our fruit-trees, our apples and pears especially, whose varieties are counted by hundreds, and I might say by thousands, if we kept all those which we have seen arise from seeds. Well-informed cultivators of seeds are unanimous in allowing that these varieties are individual, and with- out permanence, and that grafting them is absolutely necessary to preserve them and propagate them, of which M. Decaisne has re- cently given experimental proof*. Must we conclude that these varieties are the result of crossing between distinct species and races? The direct proofis wanting, but I dare affirm that it is really the cause, and that under all this multitude of unstable forms, several types, primitively specifically distinct, are concealed, to which it is no longer possible to assign their true characters. * A translation of M. Decaisne’s memoir will be found in another part of this Journal, 8 ROYAL HORTICULTURAL SOCIETY, Further, whatever opinion we may form in this respect, we must allow that these forms, not transmissible by way of generation, want in this very respect the essential character of species and true races, which is to perpetuate themselves faithfully by seed and to increase. We may say strictly that these varieties are no longer represented sometimes after ages of duration, save by a single individual, always the same, and always renewed by grafting, that is to say, by the indefinite division of its branches. But if crossings have produced these phenomena of irregular variability in cultivated plants, would it not be possible that the same cause had made them arise in plants remaining in a wild state? One is led to believe, when we cast our eyes on certain generic groups, as those of Salix, Potentilla, Rubus, &c., where species well characterized at first sight are connected nevertheless with one another by intermediate forms so numerous and so well graduated, that at last we do not know where to place the limits of these species ; thus, in spite of the most laborious studies, these genera have remained a matter of dispute amongst botanists. What renders this supposition probable is, that the species of these different groups are precisely those which occur under phy- sical conditions the most calculated to favour crossing. But it is sufficient here that two species, when crossing, give place to fertile hybrids which do not all revert to the specific types, in order that the irregular variability should come into play, and induce, after some generations, that chaos of undecided forms in the face of which all the efforts of botanical describers miscarry*. After having related how hybrids vary, it is time to examine how pure species behave themselves, when their forms are modified. Let us state first, that in respect of variability they are very un- equally gifted. There are some which we never see varying, at least in the sense which we attach to this word; there are others which vary, and sometimes within extremely wide limits. We know not what causes determine these variations; it is nevertheless allowable to believe that emigration and cultivation are not with- out influence, for we see many remarkable varieties spring up in their course. But species, when they vary in consequence of their innate tendency to do so, do it in a very different manner from * The translator of this memoir was peculiarly struck three years since with the infinite variety of forms of Salix which occur along the course of the Dee. It really seemed as if every bush possessed some character of its own, and in consequence a neighbouring botanist, who set out with the intention of collecting every variety of willow in Aberdeenshire, gave up the matter in despair. NAUDIN—ON HYBRIDISM., 9 that which we have demonstrated amongst hybrids. While in these last the form dissolves, from one generation to another, into individual and unpersistent variations, in the pure species, on the contrary, the variation has a tendency to perpetuate itself and to increase. When it is produced, one of two things takes place, either it disappears with the individual in which it took rise, or it is transmitted without alteration to the following generation, and from thence, if circumstances are favourable, and no crossing with the type of the species or with another variety disturbs it in its evolution, it passes into the condition of a definite race, and im- presses its seal on an unlimited number of individuals. It is thus that I explain the formation of those well-marked races of econo- mical vegetables, so homogeneous and so stable, of which cultiva- tion has beheld the origin, and which it preserves with so much care. If we consider only the regularity of their progress, we should take them for real species ; but their instability, when they are submitted to’ the chance of crossing, testifies their real nature. They are not species in the botanical sense of the word, they are categories in a larger species, or, if you will, confraternities of individuals similar in organization, and having a uniform livery. This homogeneousness and fixity of character are the distinctive mark of true races, as diversity and want of permanence are the mark of agglomerations arising from half-blood or hybridity. The latter, tainted with illegitimacy, are the fruit of irregular varia- tion, the former of the regulated and normal variation of the species. I could even say more willingly that they are the species itself adapting itself to new media and new finalities. I know not if facts analogous to those which I have just re- ported have been observed in the animal kingdom ; but I should not be surprised if we came some day to recognize that there also crossings between definite races are a cause of variability per- fectly individual, and that they are impotent to create new races, that is to say, uniform fellowships, and capable of enduring in- finitely. It would certainly not be without interest, if, when in- termarrying, races perfectly distinct should melt into a new mixed but homogeneous race; or if, as in plants, the crossing should have the effect of infinitely diversifying physiognomies and tem- peraments. But it is a subject for which lam not competent, and which I hasten to leave to professional zoologists. 10 ROYAL HORTICULTURAL SOCIETY. IT. Hypocaust-Heating. By C. Wrxenam Manrrtiy, Esq. Havine met with several discussions on the subject of providing bottom-heat for various horticultural objects, I was induced some time ago to turn my attention to the most economical mode, con- sistent with efficiency, of obtaining that which appeared to be very generally desired. I saw that various methods had been adopted, at varying cost and with varying success, and this had taken place more particularly with reference to vine-borders. Arches had been constructed beneath them, into which hot air had been admitted; but this appeared a very expensive mode, both in its first construction and in its subsequent working, as large quantities of fuel must be used to heat the brickwork sufficiently to be of any service for purposes of cultivation. Hot-water pipes had been passed through borders, but it did not seem easy to diffuse the heat equally by such means, though much has doubt- less been done by placing rubble over the pipes to enable the heat to circulate. Then came the experiments for other purposes by Captain Clarke, of which an account was given in the ‘ Proceedings of Royal Hort. Soc.’ vol. ii. 1861. His apparatus consisted of a long pit of brickwork five or six feet wide, covered with slates resting on iron bars, and warmed by a three-inch pipe passed down the centre. This seems to have acted extremely well for the pur- poses for which it was designed; but the slates appeared to be a fragile support, rather adapted to temporary and experimental than to permanent use, and not smoke-proof. After much consideration, I determined to try a cheap imitation of the mode in which the Romans heated the principal apartments of their villas. I was aware that builders were much in the habit of using, for roofing-purposes, a covering of three courses of ordi- nary roofing-tiles, laid in cement instead of mortar, and that this substance would bear a considerable weight, if resting on a rigid support at intervals not greater than 6 feet. I therefore adopted in a new house which I was building, the following arrange- ment. | I first excavated a chamber 2 feet 6 inches deep, at the foot of my garden-wall, and in it built up pillars of brickwork 9 inches square, to that height above the ground. These were about 3 feet 9 inches apart in one direction, and rather less than 3 feet in the other, so that at no point was the bearing quite 6 feet. These formed the supports of the floor, which was constructed on a staging of wood, which was removed as soon as the cement had WYKEHAM MARTIN—HYPOCAUST-HEATING. ‘ig sufficiently set. Previously to the construction of the floor, as I was obliged from local circumstances to place the fire and the chimney on the same side of the house, I had constructed a flue, nearly horizontal, for 7 or 8 feet across the house, in order that the heat should be delivered nearly at the corner opposite to the chimney. I was apprehensive that, without this precaution, the ‘heat might steal along the back wall and not circulate through p ) Fig. 3. Y Y ] (EE TITITELLLMIES SSS N SS255 SS 1 | | 40" 7 Soe ses iL a N SS N EV UN a N = ee ee a ‘ ROUSE ir BORDER al oe | I ' 7 ne Aare : N <|+ sees 12. 0%-->N<-----= LU. 0:-----N goa 8 if : v7. 1 Ih Fig. DZ Hp bs A N : SS { S Eo. is N N ———_ a N , ee | the chamber ; I should otherwise have only taken the precaution of making the floor thicker over the fire, by filling up the space above it with concrete, or of leaving a vacuum between the cover- ing of the fire-place and the floor, for a sufficient distance to prevent the floor cracking or becoming too hot. The fire-place consisted of an opening 23 inches wide and about 30 inches high, built in fire-brick, the bottom consisting of the cast-iron bars used for the fires by which hops are dried in my neighbourhood. The opening can be closed by means of a piece of sheet iron hung over a pulley by a chain with a balance weight, and in the chimney there is alsoa damper. By these means it was intended, when once the floor and chamber are heated, to make them part with their heat very slowly, so that, excepting in the permanent cold weather of the winter, a fire would only be needed for a portion of the twenty-four hours, and until the middle of the autumn for only a very limited portion. But in addition to the space below the hothouse, the chamber was continued under the vine-border, similarly supported on 9-inch pillars; these were not of uniform height, the outer chamber setting out with a height of 2 feet 6 inches, and dying away to 6 inches at about 11 feet from the 12 ROYAL HORTICULLURAL SOCIETY, front wall. Also in the front wall were four openings provided with shutters, by which the heat could be kept from the outer border, if it were desired that this should not be warmed. Having been requested to superintend the construction of a similar house for a neighbour, I found it better to dispense with the wooden staging on which the tile-floor was built, and to put together slabs of tileing, three courses thick, three or four days - before they were required for use. These were then placed upon their supports, and finished off afterwards, the outer edges haying been what is termed “racked off,’ and requiring to be filled in with tiles and cement to the level of the floor. This operation was easier, quicker, and cheaper than the other, and I decidedly recommend it in preference. The slabs of tiling may be made in dry aeotiae in the open air, and on any level piece of ground. In wet weather of course they should be made under cover; and if the supports are placed at 3 feet from centre to centre, which is a very good distance, they would be 38 feet square. As to the cost of this kind of work, it can be done for 6d. a foot where tiles can be had for 30s. per thousand, but would be cheaper where tiles are cheaper, which they are in very many districts. The fire-place which I used was needlessly large, and fire-bricks and fire-tiles were used to an unnecessary extent ; but even then it only cost £3 complete. That used by my neighbour, for a small greenhouse 20 feet long and 10 feet wide*, was the cast off fire-place of an old copper, and is amply sufficient for its purpose. I have since seen a material which seems to me very likely to make a good and cheap floor, but it has not yet beentried. It is an artificial pavement of cement made in blocks of any size for rather less than 6d. a foot (superficial), and with the edges so constructed as to make a thoroughly smoke-tight jomt, by pouring in liquid cement after the pieces are laid in their places (as will be seen by the figuret). This is found very durable as a pavement, * In this house there is no external border. + It will be seen by the figure that the lower sande of the tiles touch; the upper flanges are half an inch apart, and there is a groove in the edges, so that the whole forms a solid mass when the cement is poured in. a WYKEHAM MARTIN—HYPOCAUST-HEATING. 138 but has not been proved as to its power of standing fire-heat, nor as to the shrinking of the joints. The next point to be considered is the cost of fuel, the cheapness of the construction being abun- dantly plain; it is not easy to imagine anything much cheaper than £6 or £7 for the heating of a greenhouse 20x10, in- cluding an ornamental floor, every portion of which is pleasing to the eye as well as available for use. The consumption of fuel is equally moderate, and any kind of fuel can be used. I have used cord-wood, uncleft faggots, and sawdust, and the chips out of my wood yard, and I find, as I expected, that, excepting in the depth of winter, it is quite unnecessary to keep up the fire during the twenty-four hours. In the autumn four or five hours are sufficient, the magazine of heated air in the lower chamber cooling by very slow degrees, when the furnace-door is shut and the damper of the chimney pushed in. Early in November a fire was lighted at 4 o’clock and let to burn itself out; nevertheless at between 3 or 4 0’clock the following day a thermometer buried in an inner border showed a heat of 71°. The fire had consisted ofa faggot of toppings of trees and about a bushel of sawdust; and there is no doubt that any loppings, prunings, cast off pea-sticks and other garden rubbish will answer perfectly as fuel. Hence the working is, In proportion, as cheap as the original construction. And it should be kept in mind that in houses of this construction the heat is not only provided cheaply, but it is given in a different form from that usually supplied, namely as bottom-heat. This is not the place for enumerating the various plants for which bottom- heat is either indispensable or highly beneficial. They are nume- rous, but persons conversant with gardening do not require in- formation as to their number, and the experience of one season proves but little. I may observe, however, that bottom-heat in this form seems to be far superior to that supplied in a common hotbed. I transplanted some thinnings of early carrots last spring from a hotbed to my heated (external) border, expecting the transplanted plants to form a succession crop to the original bed. But to my great surprise, when they were fit for use, those in the bed from which they were taken were less than half their size. In trying to account for this, it immediately struck me that the heat of the hotbed was daily exhausting itself, whilst, by the aid of the sun, that of the heated border was daily increasing. And although it was on the outside border, whilst the hotbed had a glass frame, the result was, as I have stated, from the more efficacious action of the fire-heat as compared with that from 14 ROYAL HORTICULTURAL SOCIETY. manure. I was also greatly surprised to find that there was no tendency to dryness where the soil rested on the tiles. The drying- process merely went on by evaporation at the surface, whilst the moisture steadily increased towards the bottom. The floor being the heating power, it is also of importance to know how much of it (inside the house) may be covered with earth for plunging or growing plants, without too great a sacri- fice of upper heat. I accordingly constructed temporary borders, enclosed by slabs of wood, before making the permanent arrange- ments, to try what the house would bear; and I think I may safely say that the half may be covered. I have gone nearly as far as this, without apparently reaching the limit, for general purposes ; but of course much will depend, in this respect, upon the precise purpose to which any particular house may be apphed. In some cases more upper heat will be required than in others*. I had at first mtended trying experiments on the effect of bottom-heat upon the roots of vines; but, after I had finished my house, I found that Lord Eversley had fully ascer- tained, by four years’ experience, the beneficial results of heat in- troduced under his vine-border in very nearly the same manner. He had, in fact, made a chamber by means of tiles about 2 feet square, and had admitted under it the surplus heat of a pine-pit. The earth in a severe winter was never under 60°, and the vines throve admirably. Finding this point so fully decided, I have turned my attention to other things. I have tried French beans, early strawberries, tomatoes @ tige raide, and early carrots ; also mustard and cress and radishes sown in January (and eaten in February) in the outer border. Inside the house I have forced French beans, asparagus, rhubarb ; and am trying, with every pro- mise of success, figs, peaches and nectarines, vines in pots, and delicate varieties of oranges, and also a bed of pines which took extremely well. J ripened capsicums of different kinds, and have supplied the house with several of the ordinary kinds of flowers. My house has been inspected both by scientific and practical men, and they express a very favourable opinion of #¥s utility. For myself, I am a mechanic, and not a gardener. I am satisfied * Tf a greater amount of top-heat should be required, it may be obtained by making the bottom of the borders higher than the general level of the floor. f the borders be 4 feet wide, and the bottom be raised 2 feet on their side walls, there will be 4 feet of surface capable of radiating heat from the side walls instead of the floor, and nearly or quite as large a quantity of heat will be given out, whilst the plants will be so much nearer to the glass. C. E. BROOME—TRUFFLES AND TRUFFLE CULTURE. 15 with my project as mechanically successful, and must leave its horticultural merits to be decided by more competent authorities. If it is desirable to protect the warm border from frost, frames made after the annexed plan, 7 feet by 53, and covered with asphalted felt, are cheap, and have been found effectual. They are very light, and easily removed when dry. The legs are made of 2-inch board, cut diagonally, as in the sketch. IIL. Note on Truffles and Truffle Culture. By C. EH. Broome, Esq. THE numerous varieties of Fungi that are exposed for sale in the markets of France and Italy must induce a feeling of surprise that so little attention has been paid to their culture by the horticulturists both of Great Britain and the Continent. The Mushroom is the only species at all commonly made use of in this country; the Blewitt may sometimes, indeed, be seen in Covent Garden, but it is a species far inferior in flavour to many others of our Fungi, and it is certainly not the produce of our gardens. ‘Truffles, which are frequently seen, and so highly esteemed in Continental markets as to command a high price, are comparatively rarely to be met with in our own, and even Covent Garden can boast but of one native kind, and that an inferior one, viz. Tuber estivum. There are, however, various reasons for this neglect of Nature’s benefits that operate with us, that do not apply with equal force to our Continental neighbours, such as distressing cases of poisoning from the indiscriminate use of Fungi gathered by persons ignorant of the qualities of the various species, a danger in great measure guarded against abroad by the 16 ROYAL HORTICULTURAL SOCIETY. appointment of an official person capable of determining the noxious or innocent nature of the species brought for sale. What tends, however, still more perhaps to increase our objection to their use, is the natural inaptitude of our countrymen to acquire the art of cookery, which is a very important element in suiting these plants to human digestion; added to which, there is the difficulty of adopting new customs, or changes of diet. Were a taste for these productions, however, once established, we should soon find numerous species brought forward as valuable additions to our means of sustenance. Notwithstanding that Truffles have been considered articles of luxury, and have commanded a high price from the time of the Romans down to the present, and that it has ever been the aim of horticulturists to bring them into the number of regular garden crops, they seem hitherto to have defied all efforts to reclaim them, and to resemble, in their intractable disposition, the wild ass, “ whose house has been made the wilderness, and the barren land his dwellings, who scorneth the multitude of the city, and the range of the mountains is his pasture.”’ If this, then, be a correct representation of their character, it is a question whether it would not be easier to cultivate them by assisting Nature in her own way, than to restrict her within our limits by forcing these denizens of the forest to occupy a place in our kitchen-gardens. It would seem, indeed, that the amount of shade they demand is such as to be incompatible with the re- quirements of a garden. But let us see what has been done hitherto in the various endeavours made to grow Truffles by the assistance of art. And here we cannot do better than give the information with which the Messrs. Tulasne present us in their beautiful work on Hypogeous Fungi. They mention four spe- cies of Truffles exclusively in use in France, viz. 7. melanosporwm, T. brumale, T. estivum, and T. mesentericum, of which two, or perhaps three, occur in Great Britain. Tuber estivwm is appa- rently the only species to be met with in a recent state in our shops ; Z. mesentericwm may at times occur, but it has not yet been noticed there. Z. brwmale, if our plant be identical with Tulasne’s, has hitherto been found in England of too small a size to be worth sending to market. In Italy there are other kinds, one of which, T. magnatum, commands a higher price than any other; and in the southern parts of Italy, Sicily, Syria, and Africa, another spe- cies, Zerfezia leonis, is of common use as an article of food. The true Truffles have rough seeds, which, seen under the older C. E. BROOME—TRUFFLES AND TRUFFLE-CULTURE. 17 and imperfect microscopes, resembled somewhat a Truffle in miniature, and early writers concluded that the mature plant was merely one of these seeds largely developed in all directions. The Tulasnes have proved, however, by careful observations that they germinate in the same way as do those of most other Fungi, viz. by giving origin to delicate threads, which spread in the sur- rounding soil, and that from such threads the young Trufiles arise, probably after some kind of impregnation, which is as yet, notwithstanding the researches of recent observers, involved in obscurity. The fact of the existence of a mycelium in Truffles, resembling that of Mushrooms, must be taken into consideration in any attempt that may be made to cultivate them. The soils in which edible Truffles are found in France are always calcareous or calcareous clays, which accords generally with my own experience. Tuber mesentericum occurs, however, in ferruginous sands, as is also the case with another species, Hydno- trya Tulasnei, which, or a closely allied kind, is largely eaten in Bohemia, under the name of Czerwena Tartoffle. Messrs. Tu- lasne describe the soil of a Truffle district near Loudun, Vienne, as composed of rolled fragments of calcareous matter, mixed with fine quartzose sands, lying on a thick bed of compact marly clay, which easily splits up into thin layers. It contains, in 1000 parts, 500 of calcareous matter, 325 of clay and iron, 150 of quartz- ose sand, and 25 parts, more or less, of vegetable mould. But they attribute a still greater influence in the production of these plants to the presence of trees—a condition necessary perhaps to their growth, in order to keep off the heat of the direct sun-rays. Our authors testify, indeed, that this is not always indispensable ; and I have seen Truffles dug up on the bare sloping sides of the Italian mountains. . Some persons have supposed that these Fungi are parasitic on the roots of trees. This the Tulasnes expressly deny, on the strength of observations and inquiries instituted to that end and I can confirm them in this matter, and would remark that the frequent presence of certain galls attached to the small roots of oaks, resembling young Truffles so strongly as often to deceive me for a time, may have given origin to this error. | Some trees appear to be more favourable to the production of Truffles than others. Oak and hornbeam are especially mentioned ; but, besides these, chestnut, birch, box, and hazel are alluded to. I have generally found Zuber estivwm under beech-trees, but also under hazel, Zuber macrosporwm under oaks, and 7. brumale ‘ c 18 ROYAL HORTICULTURAL SOCIETY. under oaks and Abele. The men who collect Truffles for Covent Garden obtain them chiefly under beech, and in mixed plantations of fir and beech. The Truffle-grounds of France are remarkable for the sterility of the surface, the cause of which has given rise to many conjectures, viz. that Truffles exercise a pre- judicial influence on all plants in contact with or proximity to themselves, by appropriating their nutriment in a manner similar to the Rhizoctonia; but a more probable reason of this sterility is the frequent digging to which the Truffle-grounds are sub- jected by the collectors; for, as Truffles are not truly parasitic, it would attribute an inconceivable amount of influence to their mycelium to suppose them capable by its means of destroying all the surrounding vegetation. And we may remark, that some spe- eles occur in grassy places, as in the forest of Vincennes, according to Tulasne; and so with 7. macrosporwm and T. brumale, as I find them. It seems to be a better explanation of this sterility, so generally accompanying Truffles, that they can only succeed well where they find a comparative freedom from other vegetable growth, arising from causes independent of themselves, and that they are the result, and not the cause, of this sterility. In common with many other Fungi, Truffles do not bear to be disturbed in their early stages; so that the collectors are careful in their researches after the summer species, as 7. estivum and T. mesentericum, not to stir the ground more deeply than is abso- lutely necessary, as by so doing they would destroy the winter crop of the more valuable kinds, 7. melanosporum and T. brumale. Any disturbance of the soil in the winter, when the latter are mature, does no harm, but rather aids in their culture, by render- ing the mould more suitable for the germination of their spores and the growth of their mycehum. From Messrs. Tulasnes’ ob- servations it would seem that three or four months suffice for the development of these plants; they state that they have met with Tuber mesentericum about as large as grains of millet m the beginning of October, which must acquire their full size before the end of December; for about that time they find this species in its mature condition alone. And it is supposed that the warm rains of August are highly conducive to the fertility of the Trufile- ground, and that the abundance or scantiness of the crop depends very much on the nature of that period. These plants grow with- out any special care or tendance ; but as they are not unfrequently found, both in France and Italy, on the borders of corn-fields, where they are ploughed up in the cultivation of the land, it + Cc. E. BROOME—TRUFFLES AND TRUFFLE-CULTURE. 19 would seem that they succeed as well in ground that has been stirred and manured as in that which has been left to its natural condition. Some notion may be obtained of the extent to which the trade in Truffles is carried in France, when we read that in the market of Apt alone 1600 kilogrammes (about 3500 lbs.) are exposed for sale every week in the height of the season, and that the lowest estimate of the quantity sold during the winter amounts to 15,000 kilogrammes (nearly 33,000 lbs. weight). According to another ac- count, the Department of Vaucluse yields from 25,900 to 30,009 kilogrammes annually. The vast quantity that must therefore be procured and sold in all the French provinces where they grow, and the large revenue arising therefrom, should be a great in- ducement to the proprietors of suitable localities to attempt their cultivation in England. Many trials have been made to subject these vegetables to a regular system of culture, but hitherto without success. We owe to the Count de Borch and to M. de Bornholz the chief accounts of these attempts. They inform us that a compost was prepared | of pure mould and vegetable soil, mixed with dry leaves and sawdust, in which, when properly moistened, mature Truffles were placed in winter, either whole or in fragments, and that after the lapse of some time small Truffles were found in the compost. But the result was discouraging rather than other- wise. The most successful plan consisted in sowing acorns over a considerable extent of land of a calcareous nature ; and when the young oaks had attained the age of ten or twelve years, Truffles were found in the intervals between the trees. This process was carried on in the neighbourhood of Loudun, where Truffle- beds had formerly existed, but where they had long ceased to be productive—a fact indicating the aptitude of the soil for the pur- pose. In this case no attempt was made to produce Truffles by placing ripe specimens in the earth ; but they sprang up of them- selves, from spores probably contained in the soil. The young trees were left rather wide apart, and were cut for the first time about the twelfth year from the sowing, and afterwards at inter- vals of from seven to nine years. Truffles were thus obtained for a period of from twenty-five to thirty years, after which the plantations ceased to be productive, owing, it was said, to the ground being too much shaded by the branches of the young trees, a remedy for which might have been found by thinning out the trees; but this would not be adopted till all the barren tracts, c2 20 ROYAL HORTICULTURAL SOCIETY. called “ galluches,” had been planted. The brushwood, by being thus thinned out, would be converted into timber-trees, and the Truffle-grounds rendered permanent, like those of Poitou, which are commonly situated under the shade of lofty trees. It is the opinion of the Messrs. Tulasne that the regular cultivation of Truffles in gardens can never be so successful as this so-called indirect culture at Loudun, &c.; but they think that a satisfaec- tory result might be obtained in suitable soils by planting frag- ments of mature Truffles in wooded localities, taking care that the other conditions of the spots selected should be analogous to those of the regular Truffle-grounds ; and they recommend a judi- cious thinning of the trees, and clearing the surface from brush- wood, &c., which prevents at once the beneficial effects of rain and of the direct sun-rays. It is added that this species of in- dustry has added much to the value of certain districts of Loudun and Civray, which were previously comparatively worthless, and has enriched many of the proprietors, who now make periodical sowings of acorns, thus bringing in a certain portion of wood as Truffle-crounds each year. At Bonardeline, for instance, the annual return from Truffles in a plantation of less than half an acre was from £4 to £5. Another case is adduced in the Arron- dissement of Apt, where several proprietors have made planta- tions: the trees are left about 5 or 6 yards apart; and so soon as - their branches meet and shade the ground too much, they are thinned out. The districts of England especially suited to produce Truffles would thus appear to be situated on the great band of calcareous beds which run diagonally across the island from the south-eastern corner of Devonshire to the mouth of the Wash in Norfolk, occupying all the country that lies to the south-east of such a line, including the counties of Somerset, Dorset, Wilts, Glou- cester, Hampshire, Berkshire, Kent, Hertfordshire, and parts of Northampton, Norfolk, and Lincoln; and it is to the proprietors of lands in those districts that we must look for any successful attempts to cultivate these Fungi. A great proportion of the Truffles exposed for sale in Covent Garden comes from Wiltshire and Hampshire, and the opinions of those who make it their business to collect them comcide com- pletely with those of Messrs. Tulasne cited above. I have been informed by one of these men, that whenever a plantation of beech, or beech and fir, is made on the chalk districts of Salisbury Plain, after the lapse of a few years Truffles are produced; and Cc. E. BROOME—TRUFFLES AND TRUFFLE-CULTURE., 21 that these plantations continue productive for a period of from ten to fifteen years, after which they cease to be so. It has been observed that the species most available for culinary purposes with us is Zuber estivum, a species considered in France as of far less value than 7. melanosporum and T. brumale; and it might be worth while to obtain well-matured specimens of these species from France, and distribute them while quite fresh in some locality producing our indigenous kinds, to ascertain if we could not thus obtain a superior race of Truffles. Tuber estivum is commonly worth about half-a-crown per 1 lb. in Covent Garden, whilst in Italy Zuber magnatum fetches from fifteen to seventeen frances, and Z. melanosporum almost as much. Should horticul- turists be tempted to try their skill in the artificial production of these Fungi, they should bear in mind the conditions most suitable to their nature as above recorded. They might succeed, for in- stance, in producing them in filbert-plantations or in gardens thickly set with fruit-trees; and they should plant mature speci- mens in well-trenched ground on a calcareous substratum, and be careful not to stir the soil to any depth till the autumn or winter of the following year, in order not to disturb the mycelium ; and it would be well perhaps, in case they find a successful result, not to take too largely of the crop the first year or two, but to give them time to establish themselves thoroughly in the locality. It would seem, however, that, when once established, deep stirrings of the soil would tend rather to encourage than to check their in- crease, as giving the mycelium a lighter soil in which to vegetate, and preventing the growth of roots of surrounding trees, &c., which might deprive the Truffles of the requisite nutriment. It might be as well to try the growth of Tuber macrosporum, as it is an indigenous species, and might become a source of profit, notwithstanding its garlic odour. Those who possess woods or plantations of beech in calcareous soils, which are not already productive of Truffles, might succeed perhaps in rendering them so, by trenching patches of ground beneath the trees, so as to clear away the brushwood, grass, and roots for a considerable space, and planting ripe Truffles in the trenched spaces, and then allow- ing time for them to produce their mycelium. And when the roots of surrounding trees again encroach on the selected spots, they might be checked by deep digging around their margins. 22 ROYAL HORTICULTURAL SOCIETY. IV. Variegated Plants of the Seventeenth Century. By the Rey. M. J. Berxetey, M.A., F.LS. In looking over the manuscripts in the muniment-room of the princely mansion of the Duke of Beaufort, at Badminton, I found a list of variegated or, as the list is headed, “Strip’d and Edg’d Plants,” evidently drawn up towards the close of the seventeenth century, and, in all probability, cultivated at Badminton by the first Duke of Beaufort, though this is not a matter of certainty. In the present rage for such productions, it may not be uninteresting to see what forms were then cultivated. It will be observed that almost all are indigenous species, and, with a single exception (the tree-houseleek), not one extra-European. Some of them, moreover, as the species of Pulmonaria, cannot be regarded as diseased yva- rieties, any more than many of the exotic forms which are now so much admired and sought after. It would be almost an endless task to enumerate these ; but I have thought that it would be interesting to append a list of variegated, mostly herbaceous, plants cultivated by the Chief Baron Sir Frederick Pollock, near Hounslow, with some instructive notes kindly forwarded at my request. It is not necessary here to enter at any length into the ques- tion whether variegation is an evidence of disease or not—a ques- tion, however, which I think is decided by the fact that a variegated graft has influence on the stock; that when shoots are produced, as in some forms of Pelargoniwm which are quite white, without the least portion of green, it is, as Mr. R. Thompson has proved at the Chiswick Gardens, impossible to strike them; and that when seedlings come up with perfectly bleached cotyledons, they either fail at once or, if they linger at all, produce only chlorotized leaves*. The tendency of plants to become variegated in particular soils, as mentioned ieee is perhaps another indication of disease. I have to thank the Duke of Beaufort for his kindness in allowing me to inspect his manuscripts, and for permitting his librarian to take the copy which is here transcribed ; and to Chief Baron Pollock for his list and notes. In either case I have thought it right to follow the order in which the lists are sent, * A perfectly white and extremely beautiful Pelargonium came up from seed at Mr. R. Brown’s gardens at Wothorpe, near Stamford, and it was hoped might prove a great acquisition ; but after making about six leaves, it shared the common fate of such vegetable albinos. REV. M. J. BERKELEY—VARIEGATED PLANTS. 23 in the former the arrangement being miscellaneous, in the second alphabetical. to follow the original spelling. parentheses are not in the original. wm Cobo CO 00 NI OD OU 09 DO In the former, moreover, it has been thought best The few words which are within Strip’d and Edq’d Plants (from MSS. at Badminton). . Turkish Orreng strip’d. . Five sorts of Hollys. Silver Laurel. Gold Laurel. . Silver Phyllyrea. Gold Phyllyrea. . Plumbe-tree constantly strip’d. . Strip’d Beech-tree. . Strip’d Ash-tree. . Strip’d Mezereon. . Strip’d Nightshade. . Strip’d Wallflower. . Strip’d tree Houseleeke. . Strip’d Myrtle. ‘ Strip’d Honeysuckle. . Hdg . Strip’d Rocket. . Strip’d Sellery. . Strip’d Mugwort. . Strip’d Tansy. . Strip’d Ribwort (Plantago). . Strip’d Marjerome. . Strip’d Issop. . Strip’d Horminum creticum. . Green leaves of Primrose d Box. strip’d. . Strip’d Lylly. : Strip’d tice Williams. . Ordinarie strip’d Sage. . Amuch finer strip’d Sage. . Strip’d Grasse. . Silver Rosemary. . Gold Rosemary. . Pot Time gold. . Pot Time silver. . Mother Time silver. . Citron Time gold. . Bloody Time. . Strip’d Privit. . A small sort of Ivie strip’d. . A large leav’d Ivie strip’d. . Mint. . Strip’d purple flower Vetch. . Strip’d leav’d Auriculas. . Strip’d Wallflower (probably a different variety from the former). . Strip’d Snapdragon. . Strip’d Turnep. . Strip’d Borage. . Strip’d Rew. . Elder strip’d. . Bramble gold strip’d. . Clogweed edg’d (Heracleum). . Box strip’d. . Wing’d Pea strip’d. . Peach-leay’d Bellflower strip’d. . Wild Bell flower. . Filipendula, the leaves one side green, the other white. . Hawk Weed strip’d. . Garden Bean, all the leaves finely strip’d. . Garden Spurge strip’d. . Vineyard Thistle. . Hawkeweed strip’d. . Bramble silver strip’d. . Cowslipps of Jerusalem, the greater (Pulmonaria off.). . Cowslipps of Jerusalem, the lesser (Pulmonaria angusti- folia). . Pennyroyall strip’d. . Field Scabious strip’d. . Twayblade strip’d. . Campanula Pyramidahs strip’d. Lust of some of the Variegated Plants cultivated by Chief Baron Pollock. . Achillea millefolium. . AXgopodium podagraria. . Ajuga reptans argentea. aurea, 5. Antirrhinum majus. 6. Apium graveolens, | 7. Arabis alpina. 8, Artemisia vulgaris. 24, ROYAL HORTICULTURAL SOCIETY. 9. Arum maculatum. 40, Mentha rotundifolia. 10. Barbarea vulgaris, 4] sylvestris. 11. Bellis perennis, 42. Matricaria chamomilla. 12. Ballota nigra. 13. Brassica oleracea. 14. Carduus marianus. . Petroselinum sativum. . Phalaris arundinacea. . Polemonium czeruleum, 15. Cheiranthus Cheiri. 46, Pulmonaria sibirica. 16. Convallaria majalis. 57. Potentilla anserina. 17. Crateegus oxyacantha. 48, Prunella vulgaris. 18, Cerastium vulgatum. 49, Quercus robur. 19. Dactylis glomerata. . Rubus corylifolius. 20. Daphne laureola. 51. Rumex sanguinea. 21. Dianthus deltoides. 52. Ruta graveolens. 22. Kpilobium hirsutum. 53. Saponaria officinalis. 23. Festuca glauca. 54. Scrophularia mellifera. 24, Fragaria argentea. 55. Saxifraga umbrosa. 25 aurea. 56. Spireea ulmaria. 26, Funckia alba (marginata). 27. Galeobdolon luteum. . Stachys sylvatica. . Senecio Jacobeea. 28. Glechoma hederacea. 59. Thymus citratus. 29. Hypericum perforatum. 60. Tussilago Farfara. 30. Iris Germanica. 61. Trifolium incarnatum. 31. Iberis amara. 62 repens. 52, Juncus conglomeratus. 63. Urtica dioica. 53. Lamium maculatum. 64. Veronica chameedrys. 34, Leontodon Taraxacum, 65. spicata. 35. Linaria Cymbalaria. 66. gentianoides. 36, Lychnis dioica. 67. Verbena officinalis. 37. Medicago sativa. 38. Melissa grandiflora. officinalis. . Vinca major (reticulated). . Viola odorata. plena. Only eleven of these are contained in the Badminton list, which, however, runs as much on trees as herbaceous plants; but three more are mentioned in the notes which follow. Chief Baron Pollock remarks that he has observed in his own grounds and those around him, a tendency in wild plants to be- come variegated (always in a similar way) on their quitting their wild habitats and becoming familiar with the artificial soils pro- duced by cultivation. Ballota nigra is a good example. “I found in a tenant’s garden a beautiful specimen of this despised plant. I removed it, collected the seed, and sowed it. About 30 per cent. of the plants that appeared were variegated; and now I have plants whose seed generally produces nothing but variegated plants. I have distributed many of them. I believe all came from the same stock. I tried the same with Phalaris arundinacea foliis variegatis. I raised several thousand plants: only three were variegated*. One fine summer the sycamore (Acer pseudo- platanus foliis variegatis) had conspicuous fruit on its branches. I collected and sowed it, and raised about 2000 young plants: * JT have found this wild at Whittlesea Mere.—M. J. B. REV. M. J. BERKELEY—ON A PARASITIC FUNGUS. 25 about 120 were variegated, but (as I expected) in all sorts of different ways. There is a part of my pleasure-ground where I raised some score of the Pinus excelsa from seed; some of these are variegated, some conspicuously so. I have a deodar with white leaves mixed with the green. I have had the common gooseberry fol. var. I planted one or two score of acorns: one produced a beautifully variegated oak. I have in a plantation one well- grown fol. var. that I observed only a féw years ago. I have a common raspberry fol. var. A common holly sent out a shoot fol. var.; I made a layer of it, and, when it had taken root, sepa- rated it, and made a beautiful plant of variegated holly. It is now in the Kew Gardens. A field of lucerne always (at least here) yields several, I should say many, plants fol. var. ; a field of cabbages, several variegated, sometimes very beautiful; so parsnips, mangel-wurzel, and horse-radish. A variegated laurel is not un- common; but here they come sometimes (as one would call it) spontaneously.” V. On a Parasitic Fungus which causes Spot in Orchids. By the Rev. M. J. Berxerey, M.A., F.LS. Mr. Anprrson has recently paid much attention to the spot in Orchids, and has described four different kinds in the ‘ Gardeners’ Chronicle’ for February 18, 1865. Specimens of spot on ten different Orchids, illustrating the different forms, were submitted to me, by means of which I was enabled to confirm Mr. Ander- son’s observations in almost every minute particular. Amongst these one was evidently produced by a parasitic fungus, and, as might be expected from the deleterious action of many kinds of mycelium on vegetable tissues with which it comes in contact, it is one of the most destructive. It begins on the young leaves, causing a brownish ill-defined spot ; after a time, this exhibits different shades of olivaceous brown, and the parenchyma of the leaf becomes quite pulpy and semiputrescent. On the underside of the leaf little raised dots are seen which are caused by the cysts of a fungus beneath them. The parenchym is more or less traversed by hyaline my- celium with jointed threads, and each cyst or perithecium, which is of a pale umber, is surrounded by a broad border of hyaline, per- fectly colourless, jointed threads, the upper joints of which are more or less swollen. In this condition I have seen no fruit. 26 ROYAL HORTICULTURAL SOCIETY. REV. M. J. BERKELEY—ON A PARASITIO FUNGUS. 27 Sometimes the leaves pass rapidly into a state of decay ; but occa- sionally the parenchym dries up, the spots become bleached, but are surrounded by a dark border, and studded with the concentrically arranged perithecia. In these I have detected spores which are broader at one end and uniseptate. Occasionally, as in the case represented in our figure, the disease commences again in the same leaf; so that the incipient and old stages may be compared together. I have since had an opportunity of studying the fungus © in an intermediate condition on Lycaste Skinneri, and have seen the spores seated on their sporophores. It is extremely important that this form of spot should be ac- curately distinguished from the other forms, and I trust that the figures now given will enable any accurate observer to distinguish it, even without having recourse to the microscope. In the case of such a minute plant the cultivator cannot be expected to verify every point, and the distinction of mycelium amongst tissue is often a matter of considerable difficulty. Our figure (1) represents a leaf of Odontoglosswm citrosmum attacked by the fungus in an incipient stage at a, and past ma- turity at b. Ate appears a form of spot which, though unsightly, is not destructive like the form which is characterized by a multi- tude of pale pits. Fig. 2 is a magnified representation of one of the cysts sur- rounded by its broad fringe. Fig. 3 gives the spores, which are about ;=4,th of an inch long, seated on their sporophores and free, magnified. Fig. 4 represents a portion of the mycelium magnified. The fungus is in all probability merely a condition of some more perfect form; but it may be well, in the present transitional state of the part of mycology to which it belongs, to give it a provisional name, and it may therefore be called Leptothyriwm pernicioswm, and characterized :—Spots at first olivaceous brown, at length bleached ; perithecia at first scattered, at length somewhat concentric, depressed, surrounded by a fringe of hyaline articu- lated colourless threads; spores with two nuclei obovate-oblong, sometimes at length uniseptate. It is not, however, a very good Leptothyriwm, though the cha- racter in which it departs from the normal form of the genus pro- bably depends merely on the thick condition of the cuticle of the leaves on which it is developed, which prevents the cysts sepa- rating at the base as in other species. On the thin leaves of Lycaste Skinneri it looks much more like a Leptothyriwm. In this 28 ROYAL HORTICULTURAL SOCIETY. case the spots are sometimes 6 inches long and parallel to each Fig. 5. HM ss ay Den NMA] Hh) / | bE EL other, following the direc- tion of the nerves. On the tip of the leaf the margin is followed, and the colour paler and redder. I take this opportunity of giving a figure of a very curious form of spot, which has been forwarded to me by Mr. Warner, on Dendro- biwm densiflorwm. Whether this is really a distinct disease from the common black spot, of which fig. 1 ¢ gives the general appear- ance, I am unable to say. It differs in forming sub- -orbicular spots simulating some old encampment with a central area and three or four concentric trenches. Sometimes the regularity of the lines is deranged by two or more of the spots originally touching each other. The spots do not in general completely pene- trate the leaf, though some- thing of the concentric ar- rangement appears on the other side. This form of al size. VI. Note upon Cotoneaster Simmonsi. By J. Bareman, Esq., F.R.S. I nave much pleasure in bringing before the notice of the Horti- cultural Society a plant that cannot but prove to be extensively useful for the covering of house-front s and of garden- or terrace- J. BATEMAN—SWEET-SMELLING DENDROBIUM. 29 walls. Hitherto, after the season of flowering-plants was past, we had nothing but the well-known Orategus pyracantha to lend an air of gaiety to the situations described ; but its rich clusters of red berries are rarely to be seen after Christmas, nor are they ever produced except in sunny situations and in warm seasons. Cotoneaster Simmonsii, however (for such is the name of the plant to which I am now aiming to direct your attention), while in gaiety of appearance, rapidity of growth, and neatness of habit it more than rivals the C. pyracantha, has the great advantage of producing its bright vermilion fruit with the utmost profusion, even in a season as unfavourable as that of 1863, and a climate as inhospitable as that of North Staffordshire. It has stood quite unaffected by the trying winter from which we seem yet to have scarcely emerged, and it is now (March 4) a mass of glowing red, although not a “ hip or ahaw’”’ nor berry of any description could be found within the confines of this parish. But the birds, though they have made a complete clearance of everything else, have spared the fruit of the new Cotoneaster. I should add, that it succeeds perfectly as a standard, though when treated as such it is only sub-evergreen; nor do I think that, standing out singly, it will form a handsome tree. The history of its introduction is involved in some obscurity; but the seeds are believed to have been gathered by Dr. Hooker on the Khasya Hills, and brought by him to Kew. VII. Dendrobium hedyosmun (Sweet-smelling Dendrobium). By J. Baruman, Esq., F.R.S. Inrropucep from Moulmein by Messrs. Low, of the Clapton Nursery, to whom it was sent by Mr. Parish under the name of D. albo-viride, in allusion to the green and white hue of the flowers at the time of their opening, and for a week afterwards. Had Mr. Parish, however, waited a little longer, he would, like myself, have seen with surprise the green tint disappear from the tip, and a bright orange take its place. This change has now been for three weeks an accomplished fact in the specimen exhi- bited, and which is still as fresh as at the very first. As Mr. Parish’s was only a MS. name, and was evidently given under a misapprehension, I have ventured to change it for one which alludes to the delicious perfume exhaled by the plant, and which has a striking resemblance to that of the wallflower. D. hedyosmum belongs to Dr. Lindley’s nigro-hirsute section of 30 ROYAL HORTICULTURAL SOCIETY. this extensive genus. It appears to be a profuse flowerer, and, when more fully established, must become a general favourite. VIII. A short Note on different Varieties of Amaryllis. By James ANDERSON, THE Amaryllis, taken in the popular acceptation of the word, may be esteemed the king of all flowering bulbs, being so princely in appearance when under a proper course of cultivation, and pos- sessing flowers with such a variety of shades of colour so ad- mirably blended. ‘The species commonly called Amaryllis belongs really to the genus Hippeastrum ; but gardeners and lovers of flowers in general, if we except the botanical fraternity, are slow at changing the original nomenclature of plants, however good arguments botanists may adduce for adopting such a change. Amaryllids constitute a large order of highly ornamental plants, which collectors have found and sent home from various parts of the world; but none of them possess the decorative merits of the subject of our remarks. South America, and Brazil in par- ticular, have furnished by far the largest portion of the original species under cultivation; but it is scarcely necessary to say that these species, after having been crossed and recrossed with one another, have produced a wonderful addition in point of pro- gressive excellence. Weare chiefly indebted to A. A vitiatac Solandreflora,and A. Orga- nensis for our present fine race. But how much more interesting would it be to be enabled to hybridize Vallota purpurea and V. Sormosissima with either the original or any of the progeny of the species just mentioned! So far as I am aware, attempts at im- pregnation have hitherto defied the efforts and experiments of all those who have tried them, The Vallota, besides having an almost perfect form of petal, sends forth a scape with from six to twelve flowers on each; and if this free-flowering habit could be intro- duced into the constitution of such a variety as Ackermanni pul- cherrima, what a great advance in decorative horticulture would be obtained! That last-named variety may be said to be the very finest under cultivation, being of the most perfect velvety crimson, so as to dazzle the eye of every onlooker. The substance of the petal is of the highest order, and its form is in no way objection- able; so that, could we get a scape, which in this instance never, under any circumstances, produces more than four flowers, with J. ANDERSON—VARIETIES OF AMARYLLIS. 31 double that number, we could doubtless soon render all the other points of excellence attainable. Again, with reference to V. for- mosissima, which has a striking peculiarity in formation (the lower sepals being gathered together, and the upper petals and dorsal sepal spreading out in the usual way), we have a most brilliant crimson colour, which has no other equal in intensity, not only in the species to which it belongs, but stands unrivalled in the whole floral domain. Need it be said how desirable the introduction of such a splendid hue would be in the other sections which can boast of better formation and free-flowering properties? But, speaking to the point practically, I can say, there seem to be insuperable difficulties in the way; for, were I to relate all the various experiments I have personally conducted with a view to successful hybridization, I could fill several pages. Poor old Donald Beaton (not the least luminary in practical horticulture, and one of the most successful hybridizers that ever manipulated upon flowers) recorded his failure in this particular; and I must also record mine. I have raised thousands of seedlings, many of them not yet proved, the results of careful crossing, but they have all come from the three types first spoken of. My object in this short notice is to point out the importance of experimenting, and the particular type that it is desirable to breed from in this noble family. Unfortunately, the cultivation of Hippeasters is not so general as it deserves to be, which is so very well attested by the many beautiful sorts now in cultivation. A warm greenhouse temperature is all that is wanted, so that many amateurs in a humble position might have a collection of these for little money. Unlike Dutch bulbs, one does not require to go to market every year. When a collection is once formed, the only thing requisite is to introduce any novelty of first-class character. Their successful cultivation and flowering may be given in few words :—-Grow the bulbs in moderate-sized pots, in good loam full of fibre, with so much sand as will render the whole porous. Let the atmosphere during the growing-season be abundantly charged with moisture, especially in the evenings and mornings, so that their succulent leaves may be well provided for; and at the same time keep under thrips, to which the leaves are very subject. Withhold water as the bulbs begin to ripen, and let them have abundance of sunlight. Dry them off under the stage, or any- where else where the thermometer never falls below 36°, for from two to four months, and there will be flower-scapes and flowers in abundance. Some other day I will return to the subject. 382 ROYAL HORTICULTURAL SOCIETY. IX. A few Remarks concerning Soil and Climate in relation to the Cultivation of Fruit Trees. By Mr. W. Ingram, Belvoir Gardens. Tre marked difference which exists in the quality of the hardy fruits produced in different parts of the country intimates the powerful influence exercised by circumstances of soil and climate. Every gardener finds, in undertaking a new place, that he has many local secrets to unravel before he can succeed in meeting the requirements of the various objects of his care. I may say, paren- thetically, that some knowledge of geology and meteorology often proves of great assistance to gardeners, and saves the trials and troubles of that experience which, it is said, at last enlightens the unenlightened. Admitting, then, that we find a great diversity of soil and some marked climatic peculiarities in this country (not in every case due to the latitude of the position), and recognizing the powerful influence of these circumstances on the fruits we cultivate, the practical and natural inquiry next presents itself, Can circum- stances, naturally unfavourable, be so far modified as to enable the cultivation of such fruits as the peach, the apricot, and the pear to be successfully pursued? There can be but little doubt that, in the majority of cases, the skill of the practical horticulturist may overcome difficulties of soil more readily than those of climate ; and I am disposed to believe that a very great step towards suc- cessful fruit-culture is made when that soil is provided which is suited, by its composition, to the requirements of the tree, and calculated not only to afford pabulum for a healthy development of wood, but also for the prolonged production of fruit. As an illustration of the influence of good soil in the production of fine fruit, we find that the best examples come as often from the north and midland counties as from the south-eastern, where greater climatic advantages are enjoyed. As the circumstances within control, which unfavourably affect local climate, such as extensive tracts of woodland, waste and uncultivated land, stagnant water, &¢e., are not often placed within the scope of a gardener’s improving hand, comment on them is not perhaps necessary. I venture, however, to say that local climate may be improved by high cultivation and drainage applied to waste and neglected land: a well-drained, well-managed garden is always the warmest spot in a neighbourhood. Where superior cultivation is not the rule, one very important climatic circumstance, the fall of rain, may, at all ers MR. W. INGRAM—SOIL AND CLIMATE. 33 events, be diverted from fruit-borders, should it happen, as it not unfrequently does, that a heavy fall occurs just at the ripening period of, for instance, the peach crop ; a provision for turning it from the peach- and fruit-borders should, if possible, be in the possession of gardeners. For two years past (1863 &1864) the rain- fall, with but few exceptions, throughout the country has been below the average, and fruit-crops have been most abundant ; this fact seems to suggest what I have hinted above as desirable—the employment of artificial means to restrict the fall of rain to cer- tain choice fruits, to a limited extent: thus, if an annual fall of 18 inches of rain be adequate, let all above that amount be diverted. I have long employed shutters to cover vine-borders, and I am satisfied that Ienjoy a great advantage in being able to control the amount of rain upon them. I may, I think, with propriety supplement these remarks on soil and climate, by a description of two plans I have devised to counteract the ungenial influences of a cold climate and a moist clay soil, and to give the advantages of increased warmth and dryness to such fruit-trees as pears, peaches, and vines. The first was designed specially to keep the roots of dwarf pyramidal pear _or other trees, the growth of which it was desirable to restrict within defined limits, to save the necessity of removal for the prevention of growth or severe root-pruning, and also to secure to the tree the exclusive advantage of a suitable compost and ex- clusion from the chilling influence of a clay subsoil. - I excavate a space according to the probable requirements of the tree to be planted, say 3 feet square and 3 feet deep; the bottom of the excavation is paved with stone or brick, or concrete, the sides built up with 43 in. brickwork ; two small holes are left towards the bottom in the brickwork, so that roots at some period may, if requisite, be permitted to seek additional nutriment ; the position of the holes being known, the excision of the roots is a matter of easy accomplishment, if found necessary. The bottom of the compartment is covered with drainage or rubble to the depth of 6 inches, so that the bricked-in space is like a well-drained flower- pot. ‘Two boards, the size of the space, will be effectual at any time in turning off excessive or undesired rain. The next contrivance for fruit-trees may be connected with the foregoing with advantage. It consists of a series of hollow brick pillars, 43 in. brickwork, raised to the height of 5 feet, and 2 feet square, giving 40 feet of exposed surface for each tree ; each pillar is connected with an underground flue, thus connecting in one VOL. I. D 34 ROYAL HORTICULTURAL SOCIETY. heating-system the whole of the pillars. These fruit-pillars may be made ornamental, and surmounted with a vase; covered with closely-trained fruit-trees, their appearance is by no means un- sightly ; and I fully anticipate that fruit of the highest excellence may be obtained by their use. To those who cannot command a fruit-wall, and who desire well-ripened peaches or pears, these pillars afford every advantage. The accompanying sketches may help to conyey an idea of my inventions. “Vy 22 Se Rar wees : Se Mao oes Hs t = l ts aN ‘ee V7 Fig. ts Brick compartments for fruit-trees, the front wall being omitted ; C without soil, D partially filled. MR. W. INGRAM—SOIL AND CLIMATE. i ay = = > ‘SONP-Sutpouttoo pur savp[rd-ymaz jo uvtd-puno.ay ‘OnP-SuryO9UUOd Jo uOyISOg “g ee ae — "e “BLT 00} G Jade oourysiqy MERLE ga Fy ‘adenbs 4ooy G ¢ ¥F ysiy yoy G savprd-qmayq — baa es Bae = NS OGD a PD = DZ 86 ROYAL HORTICULTURAL SOCIETY. X. On Variability in the Pear-tree, the result of Experiments made at the Museum of Natural History from 1853 to 1862. By M. J. Decaisyr*. TE almost unlimited and still increasing number of varieties in fruit-trees, pulse, and all economical vegetables in general, is a phenomenon to which science has hitherto paid little attention. There is the greater reason to be astonished at this, since it has been remarked even by persons most unaccustomed to the study of plants, and since, from the earliest times, it has been an object of importance on the part of cultivators. Writers of antiquity—Theophrastus, Pliny, Columella, and others, like those who have succeeded them in ages nearer to the present, the brothers Bauhin, Ch. Estienne, T. Dalechamp, &c.— have described a tolerably large number of these varieties, espe- cially in fruit-trees, where they were the most apparent ; but one would in vain search for their origin in their writings: though they let us vaguely suppose that they are, or may be, the produce of cultivation, none of them say positively that any particular new variety sprang from any other; none of them explains why they have gone on multiplying from age to age. Are these new forms, then, as has been recently alleged, real species, which re- mained unrecognized up to the time when it was proposed to submit them to cultivation? or are they only modifications of long-known species, endowed with the faculty of assuming differ- ent habits, according to circumstance of place and climate? It may seem astonishing that such a question should be brought be-— fore the Academy, so natural does it seem to believe that species are subject to variation; but we shall see presently that this question is not one of those which we ought to leave without ex- amination: if it is important as regards practical agriculture, it is not less so as regards science itself. Two schools, or I should rather say, two different hypotheses divide botanists at the present moment. The most ancient, which I may call that of the Linnean school, admits the variability of species within limits, which, to say the truth, it is not always easy to define; hence those large, polymorphous, and sometimes vaguely- defined species, though in general easily characterized by a short specific character. The other school, which is more especially modern, and which, I believe, may be called the school of immuta- * Translated from ‘Annales des Sciences Naturelles,’ 4 série, vol. xx. p. 188 (1864). M. J. DECAISNE ON VARIABILITY IN THE PEAR-TREE. 37 bility, denies, in the most formal manner, variability in the vege- table kingdom. In its opinion, specific forms are never in any degree modified, and if two congeneric plants present appreciable differences, however feeble they may be, these two plants are from the origin of things species radically distinct. From this point of view, which has found in M. Jordan of Lyons a very eloquent and conscientious defender, all races and all varieties ad- mitted by the other school become so many species; and so local floras are immensely increased when they have for their authors men of this stamp. That Linnean botanists have made species of too great latitude, by uniting under the same specific name forms which are really distinct, is what I am far from contesting ; but these are errors of detail which are inevitable in a first review of the general flora of the world, inconveniences which experience corrects every day. But we should be wrong, in my opinion, if we concluded from thence the condemnation of the principle which has directed them, viz. the variability of specific types. We must, however, acknow- ledge that their opponents have a right to require a proof of this variability, which is almost always more hypothetic than matter of demonstration. It is here, in fact, that we have thg point of the question ; for if what we have considered as simple alterations of amore general type which is really immutable, if our supposed varieties are species, in spite of their apparent affinities, we must allow that our adversaries are right, and admit into our descriptive catalogues all these slight species, whatever may be their number, and however embarrassing a too extended nomenclature may be- come. But is it in this direction that we really have improved ? above all, is this the truth? Many good authorities doubt it; not only are they afraid of seeing descriptive botany degenerate into a science of words, but they ask besides, if, after all, the im- mutability of forms is better proved than their variability? One way alone is open of solving the difficulty ; it is useless any longer to argue, we must observe and bring forward facts; and it is with this view that I have undertaken the experiments with which I have to occupy the Academy. In the eyes of M. Jordan* all our races and all our varieties of fruit-trees, and amongst others pear-trees, are distinct invariable species, remaining always identical through all possible genera- * Alexis Jordan, “On the Origin of different Varieties or Species of Fruit-trees and other vegetables generally cultivated for the necessities of Man,” 1853, Paris, Bailliére, p. 30, &e. 38 ROYAL WORTICULTURAL SOCIETY. tions, from which it follows that these trees do not spring, as is commonly believed, from a single or even from a small number of specific types which cultivation has caused to vary, but from as many primitive types as there are discernible varieties*. Thus, to confine ourselves to the pear-tree, of which nurserymen already reckon more than five hundred varieties, we must admit at least five hundred primitive species, and as these exist nowhere in a wild state, logic induces M. Jordan to conclude that their domesti- cation ascends to the antediluvian period of man, and that we only possess them now because they were preserved in the ark which saved Noah and his family. Strictly speaking, the fact may be conceived as possible; but how many suppositions must we heap up, one on the other, to render ‘it probable! Is it not more simple to explain this always-increasing multitude of congeneric varieties by the principle of the variability of species, if this variability can ‘be demonstrated? But I believe that this has been done. The Academy knows already the astonishing transformations which have been observed recently at the Museum in the group of gourds and melons, where the varieties are counted by hundreds ; the facts which I have to describe in the pear-tree are of the same order, and lead to perfectly similar conclusions, which are, on one side the contemporary appearance of new races, on the other their instability by crossing, and particularly the specific unity of all the races and varieties of cultivated pears. In 1853 I sowed numerous seeds of pears, chosen the previous years from four varieties, reckoned as very distinct by all nursery- men, viz. the old, universally-known Poire d’Angleterre; the Poire Bosc, whose form is that of an elongated calabash, and the skin uniformly cinnamon; the Belle Alliance, short, and shaded with yellow and red; and the Poire Sauger, a wild, or almost wild variety, so named because the leaves of the tree remind one, by their white down, of the Common Sage. For this last sowing I employed all the crop of a tree which grows by itself on the road from Marcoussis to Gué. The seeds of these pears sprouted the same year in which they were sown, with the exception of those of the Poire d’Angleterre, which did not do so till the following year ; and this was the case in two different sowings in 1853 and 1854, without my being able to discover the cause. A small number only of these trees has begun to bear fruit, which I regret, because the results which they would have yielded, if all had borne fruit, would have been much more varied and, in * Jordan, op. cit. p. 32, ke. } bid. p. 89, &c. M. J. DECAISNE ON VARIABILITY IN THE PEAR-TREE. 39 consequence, more conclusive than those which I have to submit this day to the Academy. We may see, nevertheless, at the first glance, on an inspection of the coloured figures, how much the fruit, in each of these categories, has been already modified in the first generation. Thus, in the variety Sauger, four trees which have fructified have yielded four different forms of fruit; one ovoid and entirely green; a second short and almost apple-shaped, coloured with red and green; a third still more depressed; and, finally, a fourth, regularly pear-shaped, twice as large as the foregoing, and uni- formly yellow. rom the Belle Alliance nine new varieties arose, of which not one reproduced the mother variety, in form, size, colour, or time of ripening. There were two especially which L shall mention; one for its size, more than twice that of the Belle Alhance, the other for its short major axis, calling to mind the apple-shaped pears or bergamots. The Poire Bosc produced three new fruits different from the type; one of the three so like one of those obtained from the Sauger, that one could scarcely distinguish it. The variations were not less in the Poire d’Angleterre, where six trees yielded six new forms, so different from each other and from the mother form, that there are amongst them most of our old varieties ; one of them has even yielded winter fruit similar to the Saint-Germain. Jt is not only in the fruit that the trees from the same variety have differed, but also in their various precocity, in habit, and in the shape of the leaves. These differences are striking when the trees are near each other in the same beds of the garden; each tree has a different aspect. Some are thorny, some thornless ; these have slender wood, those are thick and stubby ; in some speci- mens of Poire d’ Angleterre, the variation has proceeded so far as to produce the first year from seed, lobed leaves like those of Hawthorn, or Pyrus Japonica. Nothing, indeed, would have been easier than to make of these young trees almost as many new species, however slightly one might have adopted the ideas of the modern school, without knowing from whence they were derived. It is not possible to doubt that cultivation is a great source of variation in plants, and this from the complexity of the elements which it brings into play. The transformations which they un- dergo in our gardens are rapid in comparison with what takes place in nature; thus, for example, the poppy, the cornflower, and the larkspur always remain very uniform in a wild state, while in our flower-beds they are modified in the most remarkable degree. 40 ROYAL HORTICULTURAL SOCIETY. The flowers of the poppy pass from a bright red to pure white, or even black, by the extension of the deep-coloured spot which exists . at the base of each petal; at other times they are shaded with two colours ; or, finally, they become extremely double instead of single as they were in the normal state. The flowers of the cornflower, and those of the larkspur, so uniformly blue in the fields, almost always change their colours after some years of cultivation; they become white, rose-coloured, tinged with violet, or wholly violet ; it is rare that they preserve their primitive tint. I may remark that we cannot attribute these variations to crossing with other species, since the flowers are fecundated by their own pollen some time before the expansion of the blossoms, and since these varia- tions in the end become hereditary, like the specific characters. The inheritance of forms is not, then, the exclusive privilege of species ; it belongs likewise to varieties, or to races whose origin is well known, and in consequence it is not an indisputable criterion by which to decide that any particular form allied to some other, found in a wild state and recognized as hereditary, is on this account a different species from this last. The theory of Van Mons is very frequently at fault: witness an example taken from amongst a hundred others, and which naturally takes its place here. According to this pomologist, we may anticipate the quality of the fruit of a young seedling tree by the inspection of its wood. Ifthe wood resembles that of known good varieties, the fruit will be of good quality. The Chaumontel, Crassane, Archduke Charles, Bergamotte de Pentecédte, the Ur- banist, are universally esteemed as first-rate fruit; nevertheless the trees differ strangely from each other, some having long slender shoots, others thick and firm, &c. This little group of trees, which I take by chance, offers almost all the variations in size, habit, and wood which are known in the pear-tree. The experi- ments quoted above—experiments which show that from the same sowing we have thornless and thorny trees, straight and divaricate, smooth and downy, &c.—come even more closely to the point. There is no truth, then, in the assertion of Van Mons, when he says that the appearance of the wood of the Passe-Colmar is re- produced in the Frédéric de Wurtemburg, that the Saint-Germain has given its form to the Urbanist, that the Rance exactly resembles the Gracioli, and the Doyenné the Poire de Pentecdte, &c. Everything is variable in the pear-tree, even the nature of the sap. The proof of this latter circumstance is found in the very different success of grafting according to the choice of stock. All M.J.DECAISNE ON VARIABILITY IN THE PEAR-TREE. 41 races and varieties of pear-tree take on the pear-tree, but all do not succeed on the Quince; for example, the Rance*, Clairgeau, Bosc, Duchesse de Mars, &e. When we wish to multiply these varieties, and for want of the wild pear we are obliged to employ the Quince, the last is grafted on the Jaminette, the Sucré-vert, the Crassane, the Abbeville, very vigorous species, which are suited to this sort of stock; and when the grafts have taken, they receive in their turn varieties whose sap does not sympathise with those of the Quince. It is an operation known and practised by all nurserymen. The relative size of the flowers and appearance of the foliage offer no less striking variations. Certain varieties, as the Catillae, St. Gall, Epargne, de Vallée, &¢., together with wide, rounded and undulated petals, have blossoms 5 or 6 centimetres (from about 2 to 24 inches) broad; and their trees, in the early stage of foliage, are as white and cottony as the Sauger. Others, like the Heéric, Sylvange, Fortunée, &c., with oval or lanceolate petals, have flowers half the size, their diameter not exceeding 3 centimetres (1i mech). Finally, we possess at the Museum a pear-tree wrongly named Chartreuse, whose linear-lanceolate petals are scarcely 3 millimetres (scarcely + inch) broad and 9 millimetres (about 2 inch) long. It is vain, therefore, to seek for specific characters in the proportions of the flower or the parts of which it is made up. Can characters, however, be found in the size and form of the fruit? We have already seen these elements vary in the experi- ments detailed above, and these were confined to four varieties, of which a few trees only have borne fruit. The variations would have been far greater had I been able to try all the known va- rieties of pear-tree. We may judge of the enormous differences which occur in respect of size, when I call to mind that the wild pears, which botanists have somewhat prematurely called Pyrus longipes and Pyrus azarolifera, do not exceed the size of a pea, while our enormous pears called Poires d’Amour and de Livre equal in volume a middle-sized melon—that is, twelve or fifteen hundred times as much. Analogous remarks may be made as to the colour of the flesh, which is green, yellow, salmon-coloured or red. But perhaps it may be said these are precisely characters * At least, if they do succeed, though they may bear abundantly, the fruit is extremely small, as, for example, in the Beurré Rance, and scarcely to be recog- nized when compared with well-grown samples.—Eb. 4.2, ROYAL HORTICULTURAL SOCIETY. which show a specific distinction in these different kinds of pear- trees. Assuredly I should ask nothing better, for nothing is so pleasing to the mind of a botanist as definite characters, those gaps in the series of congeneric forms, which at the same time facilitate his labour and furnish a fulcrum to his nomenclature. He is satisfied when these specific, well-defined divisions agree with his ideal notions of nature; but unhappily it is not so in the group of pear-trees: from the microscopic Pyrus azarolifera and longi- pes we pass by an insensible transition to the Mille-au-godet, a pear cultivated in the neighbourhood of St. Brieue, which is scarcely larger; from this we arrive at the Sept-en-gueule, or little Nutmeg, another variety, or rather assemblage of varieties, in which the fruit varies from the size of a woodnut to that of a wal- nut. At the same time a multitude of races and subraces, va- rieties and variations of wild pears of all sorts of forms and magni- tudes, from that of the Mille-au-godet to that of our common cultivated pears; and in these we pass from the smallest to the most gigantic by an indefinite series of intermediates, in which every difference of form and colour, from the Musette and Corne- muse, which are so curiously elongated*, to those depressed pears which have been justly compared to apples. Tow then, I say, can we lay hold of a specific character of any value in an assemblage in which all the most extreme forms are united by insensible and numberless gradations? It is looking for what nature has not done, and forcing her to enter into an artificial category. To whatever hypothesis we may lean, as regards the notion of a species, we cannot help seeing that it presents itself under dif- ferent aspects, sometimes restricted within narrow limits, strictly characterized, and not varying sensibly, but sometimes also prodigi- ously broad, polymorphous, and, so to speak, divisible ad infinitum. Pear-trees form no exception; and many other genera of plants offer the same profusion of secondary forms, and are an equal source of perplexity to classifiers. Almost all pomologists, at least those who are worthy of the name, have tried to classify pear-trees ; but all have failed, in so far at least as they have never been able, in consequence of the inter- * These modifications of form in the fruit of the pear-tree recall in the most striking manner those which occur in the esculent pumpkins, melons, and gourds, where we see equally the fruit elongated till it becomes quite serpentine, while others, on the contrary, are abbreviated and flattened at either extremity. (See Naudin, Ann. des Sc. Nat. t. vi. 1856.) M. J. DECAISNE ON VARIABILITY IN THE PEAR-TREE. 43 mixture of characters, to make an arrangement in the least degree natural, and which would embrace all the known varieties. At the commencement of.my studies, like my predecessors, I thought that I might undertake this work with some chance of success ; now I am disabused of this hope, and I do not fear to declare that every classification will be purely artificial. The only useful prin- ciple which can be adopted here will be, I think, the time of the ripening of the fruit, because in an economical point of view this consideration predominates over all others; and even here, again, we must assign very wide limits to these seasons of maturity. Neither the form of the fruit, nor their size, nor their colour, nor their flavour, any more than the habit and appearance of the trees, the colour of the wood, the size of the leaves and flowers, &c., can afford any base for a classification, because all these characters are purely individual, which they do not transmit faithfully by way of generation, and which, as there are not want- ing examples to prove, change soon in one and the same individual in consequence of local circumstances which one cannot always explain. The partisans of the plurality of species may object, in the group of trees with which we are occupied, that if in this multitude of intermediate forms we are unable to recognize distinct specific types, this depends on the fact that the primitive species have in- tercrossed thousands of times; that their fertile hybrids have ‘increased in an enormous degree the number of crosses, and that from thence have sprung these innumerable forms which are the despair of classifiers. Iam far from denying the fact of these crosses or of their influence; I say even that nothing appears to me more probable; at least itis not possible to doubt it, when we see what takes place in a pear-orchard when in flower, where the bees, attracted from a distance of a league, pilfer from morning till evening, mingling the pollen of all the varieties, and disseminating it on stigmas for which it was not destined by nature. But we may remark that these impregnations, which are supposed to be unnatural, are always fruitful, that all the flowers which receive pollen from any kind of pear whatsoever, set their ovary, and that the fruit when developed always contains fertile seed*. * IT know no apparent exception to this fertility, except in the Poires sans pepins and Comte de Flandre, whose fruit contains no seeds; but this does not prove a want of power in the pollen, which, besides, might as well be that of its own parent tree as of a tree of any other variety. In fact, I have ascertained 4A ROYAL HORTICULTURAL SOCIETY. But, I ask, will this constant fertility after all possible crosses, afford a proof of the difference of primitive types? Precisely the contrary conclusion is suggested; and when we haye seen the same fact produced in other species, at the same time well charac- terized, and quite as polymorphous as the pear-tree, for example in the potiron (Cucurbita maxima), the pumpkin (C. Pepo), the musk gourd (C. Pepo), the bottle gourd (Lagenaria vulgaris), and the melon (Cucwmis Melo), where likewise the strangest differ- ences of form, size, colour, consistence, and taste are seen in the fruit, one is forcibly led by analogy to admit in the pear-tree only a single natural species. Besides, we may remark, in all specific groups which are so polymorphous, it is the fruit which varies the most, and also that in all these the fruit is inferior, that is to say, formed by a receptacle in which the ovaries are immersed. The adherence of the ovary should seem then to be the organographic condition which has the greatest tendency to variability in the fruit. What we know of Umbelliferze, Cupulifere, and the genera Medlar and Rose, in which equally the fruit is inferior, certainly does not weaken this kind of view. Does grafting, as some maintain, modify the character of varieties ? For my part I do not think so; I have never at least observed anything to confirm this opinion. Duhamel, for example, remarked a century ago that the Imperial Oak-leaved Pear (a curious variation of foliage which I might have indicated before) had never more than three cells in the ovary instead of five. This is the case still; the fruit has only three cells, notwithstanding it has been propagated by grafting only since the time of Duhamel. Many other facts of the same nature might be brought forward in support of the inability of the graft to modify the characters of varieties,—those, for example, which the flavour of fruits, so re- markably different from each other, affords. It is, then, an error against which it is well to protest, viz. the belief that the degeneration of our races of fruit-trees in a conse- quence of the constant practice of grafting for their propagation. Not a single authentic fact can be adduced in its favour; those which have been alleged depend on entirely different causes, that this defect of seed depends, in the first of these varieties, on the more or less complete abortion of the ovaries, and in the second on an absolute want of ovules. —J.D. - In Cucurbita moschata, the fruit of which, at least in the Courge pleine de Naples, closely resembles the pear in many respects, there is sometimes a total abortion of ovaries, and the fruit beneath the rind consists merely of a mass of parenchymatous tissue.—Ep. M. J. DECAISNE ON VARIABILITY IN THE PEAR-TREE. 45 amongst which we must place in the first line that of climates, or of soils incompatible with the peculiar exigencies of the variety’ and very frequently also bad cultivation, or the abuse of pruning so frequent in our days, which would fain pass for perfection. Our old pears, so justly esteemed one or two centuries ago, are still the same as when they were more in request; they ripen at the same seasons, and keep also as perfectly. It suffices, in fact, to quote the Epargne, Crassane, St. Germain, Doyenné, Chaumontel, Winter Bon Chrétien, and Easter Beurré, known now as the Doyenné d@’ Hiver, to be convinced that our old varieties have lost nothing of their good qualities. If we neglect them, it is not be- cause they have degenerated, it 1s only because the nurserymen are interested in sending out their novelties. This degenerating of old races, accepted without opposition, is in reality nothing more than one of those works of industrial acuteness so easily excused in our days. Is it then more true, as Van Mons has asserted, and as most pomologists believe, that the seeds of good kinds of fruit produce crabs with harsh fruit, reverting to what are supposed to be the specific types? I do not hesitate to affirm the contrary; and I defy anyone to quote a single example of a fruit of any quality impregnated with the pollen of its own flower, or of others of the same race, whose seeds have given rise to a crab. If a variety of merit is impregnated by a variety with harsh fruit, there will cer- tainly spring from its seeds new varieties, which for the greater part, if not altogether, will be inferior in quality ; there may even be found some whose fruit shall be as bad as that of the wild plant which has furnished the pollen; but this degeneration, if we may give it the name, is nothing more than the consequence of an ill-assorted crossing. We may consider it certain that every distinguished variety of pear-tree, and I may say of all our fruit- trees, if it is fecundated by itself alone, will give birth to good fruit ; it may and will probably differ, sometimes by one character, sometimes by another from the mother variety, but no one will assume the characters of the wilding, any more than our Can- taloup Melons resume, by sowing, the form, size, and taste of the little wild melons of India, or our cauliflowers or cabbages revert to any of the wild kinds so different in habit and quality which grow on the cliffs of the Ocean and Mediterranean. Whatever then the partisans of immutability may say, species in the vegetable kingdom are endowed with great flexibility ; and it is not a vain hypothesis which refers to the same specific type AG ROYAL HORTICULTURAL SOCIETY. races and varieties, sometimes very different in appearance, but having the same morphologic organization and capable of breeding with each other by crossing as members of the same family. I allow that there will always be doubtful cases, even after the proof of fertile crossing in the whole series of possible generations ; but this is no reason for separating, as so many primordially dis- tinct entities, what so many observed facts and so many analogies prove to be able to proceed, by way of evolution, from a single primary specific type. If we transport any one of our race of pear-trees into all the regions of the globe wherein it is able to exist, it will tend to place itself in harmony with the media, and we may be sure that after some generations it will have given rise to new and numerous varieties. This fact, which is realized in the sight of man inall the economical plants which are spread through the globe, affords the key to those polymorphous species, so em- barrassing to the botanist, and which have become so only because nature has itself spread them over immense extents of country. XI. Note on the Floral Organogeny of the Pear-tree. By M, J. Drcaisne. M. Decatsne had already expressed his opinion on the value of certain specific characters in a paper addressed to the Société Bo- tanique de France, and which was published in the ‘ Bulletin’ of the Society, April 83,1857. The former part of this communica- tion touches on the topic which is discussed at large in the pre- ceding paper. He states decidedly his opinion that botanists ought rather to condense species in referring them to types which are really natural and stable, instead of multiplying them, as has been the fashion for some years past, and supports his views by a reference to Dr. Hooker’s introductory essay in the ‘ Flora Indica’; and he does not hesitate to assert. that some of his work, as that of the Plantaginee in the ‘ Prodromus,’ if it were to be done over again, would be done on a wider principle. {it is not necessary to quote more from the former part of the paper, but there is a part at the close which will form a fitting appendix to the valuable memoir of which a translation has been given above, as it treats on the nature of the parts of fructification in the pear-tree ; and there is more reason for reproducing it here as it is not very generally accessible. “When we examine very young flower-buds of the pear towards M. J. DECAISNE—FLORAL ORGANOGENY OF THE PEAR-TREE. 47 the month of October, that is to say, in shoots which will not be developed till the following year, we find that they are ovoid, sessile, scarcely as large as the head of a pin, and crowned with five appendages converging towards each other, which are the rudiments of the sepals. On dividing them vertically, we remark at the base and on the walls of the cup which is circumscribed by the nascent calyx, slight protuberances or papille, of which five, more interior and arranged symmetrically round the ideal centre of the cup, are presently distinguished from the rest by their more rapid development. These are the carpels, which at first are in- dependent of each other, and free from any adhesion with the surrounding organs. Almost from their first appearance a slight channel is marked on their interior face, an indication of the line of juncture of the borders of the carpellary leaf. A. little later the cell or cavity which each of them forms between its folded edges becomes visible, and still later two ovulary papille are dis- cernible, springing at the base of the cell from the very borders of the carpel. “T have just said that at first the carpels are free in the receptacle of which they occupy the centre; nevertheless, when the fruit is perfect, they are deeply imbedded in the parenchymatous and succulent tissue of the fruit. How then does this take place, which seems in contradiction with what we had observed at first ? This is what I am going to explain in a few words. “ Almost at the time that the young ovaries spring from the base of the receptacle under the form of obtuse cones, a new cellular tissue is produced on the walls of the receptacle, which has daily become deeper and more bell-shaped. This tissue gradually thickens the walls, and forms what is called the perigynal disk of the flower. This new parenchym reaches presently the central whorl, moulds itself upon it and agglutinates the carpels, pene- trating the little interstices which are left between them. Never- theless it does not completely cover them, for their interior borders, those which correspond to the suture, always remain free. This additional tissue is easily recognized even in ripe fruit; it is what is called the heart of the pear; it is always situated within the inclosure traced by the stony granulations which characterize the fruit. I have no need to add that at the time when this pheno- menon is accomplished, the summit of the carpellary cones is elongated into the style, and that the disk, increased in height as well as thickness, carries the stamens and the petals very far from the point at which they had originated. 48 ROYAL HORTICULTURAL SOCIETY. “ But these are not the only changes which have taken place in the flower and very young fruit, there is another which is not less worthy of attention, and without which the fruit would remair incomplete. We have seen that at first the bud was sessile, or nearly so; gradually the rudimentary peduncle is elongated and assumes the well-known form, but at its upper extremity it passes insensibly into the young fruit, which in fact is only a continuation of it. It is in reality in this dilated part of the peduncle, which we have called the receptacle of the flower, and which is situated below and around the disk of which we have just spoken, that the principal increase takes place, at least in the greater number of pears. It is then the peduncle itself which is here transformed into the fruit, if we mean by this word the succulent and esculent tissue, absolutely as in Anacardiwm and Hovema. If any doubt could remain about the matter, it would be removed by the exa- mination of those abnormal fruits, like that represented by M. Naudin in his “ Note on the Structure of the Flower in Cucurbi- tacez,”’ which are real pears formed entirely at the expense of the peduncle, since having neither heart nor carpels, nor vestige of calyx leaves, they have never been terminated by a flower. “IfI have made myself understood, we shall see that the struc- ture of the ovary in the pear differs in nothing from that of the ovary in other vegetables, and that it is altogether conformable to the general plan of organization explained by our illustrious masters, R. Brown, DeCandolle, and Jussieu. It is not then necessary to bring forward the axis, to which appeal is made at the present day so often and so willingly, when it is required to explain the structure of flowers or fruit. 1 go further, and if I am not deceived, it is not impossible to refer to the common plan of organization, ovaries with a central free placenta, of which the differences from ordinary ovaries would in this case be more ap- parent than real. A strong presumption in favour of this mode of view, if not an absolute proof, is afforded by the very homogeneous family of Melastomacez, in which the most opposite modes of placentation are found*. Thus, for example, in the suborder of Melastomex, properly so called, whose ovary has from two to twenty cells, the placente are axillary, that is to say, altogether adherent to the central columella which results from the line of junction of the carpellary leaves; in Hwyckia, where there are four cells in the ovary, they are, on the contrary, parietal, or if the phrase is preferred, fixed on the middle of the cells. Between * See ‘Rumphia,’ in which I published in 1834 the analysis of this family. ON SOME HYBRID VINES. 49 these modes of placentation we find that which characterizes the Astronie (Astronia and Microplacis, Bl.), in which the placentze are situated at the bottom of each of the two cells of the ovary at the base of what may be called the columella. There is but a step therefore from the unilocular ovary to the free central placenta of Memecylex. If the carpellary leaves of Astronia, instead of being inflexed towards the centre of the ovary, were simply soldered by the margins, remaining ovuliferous at the base, we should recon- struct the unilocular ovary and the central placenta of the Me- _ mecylee and Spathandra. The great affinity which exists between the different members of the family of Melastomacee does not allow us to admit amongst them differences of placentation so radical as those which would result from the prevailing theory on the organogenic nature of the free central placenta—to suppose, for example, that in this same family of Melastomacee the placentze grow, indifferently, sometimes from the carpellary leaf, sometimes from the elongated axis of the floral whorl. It seems to me more natural, and at the same time more probable, that in all the plants of this vast and beautiful family, the placentation, in spite of appearances, is always a dependence of the ovarian leaves. I might bring forward precisely similar modifications in the different groups of the family of Aroidez, Caryophyllacee, Portulacee, &c. ; and if the hypothesis is just in the families which I have just quoted, why should it not be equally so for Myrsinez and Primu- laceee.”” XII. Note on the effect of crossing some of the Southern Vines of France with the variety Le Teinturier. Monstevur Henri Bovscuert has addressed to the Royal Horti- cultural Society a short pamphlet, of which the full title is given below*, with the request that a report of it should be prepared, with a view to making more generally known the curious fact which is the result of his experiments. The pamphlet, it may be remarked, has already been presented to the French Academy, and inserted in the ‘ Comptes Rendus,’ tome Ix. p. 229. * Collection de vignes a suc rouge obtenues par le semis aprés le croisement des cépages Méridionaux avec le Teinturier, par M. Henri Bouschet, Membre de la Société Centrale d’Agriculture et Secrétaire de la Société d’Horticulture de V’Hérault. Montpellier, 1865, 8vo. pp. 11. VOL. I. E 50 ROYAL HORTICULTURAL SOCIETY. Few experiments in comparison have been made towards im- proving the vines of France by intercrossing, notwithstanding their great importance. One of the main objects with French vine-growers, is to obtain as deep a tint in their wine as possible, since it is usually mixed with water. For this purpose, about forty years ago the father of M. Bouschet introduced very extensively into his vineyard the variety known as Le Teinturier. Though, however, the in- troduction answered so far as improvement of colour went, the increased value in this respect did not compensate for the com- paratively small produce of the variety in question. Unwilling, however, to give up the matter as hopeless, he determined to try if he could cross some of his more productive varieties with the Teinturier. There was some difficulty about this, as the Tein- turier flowers eight or ten days earlier than most of the more generally cultivated varieties. By some means, however, which are not detailed, the flowering was retarded, and crossing at length effected successfully with the varieties Aramon, la Carignane and le Grenache (Alicant de l’ Hérault). The bunches on these artificially fertilized plants consisted of grapes of two kinds, the majority of which had the normal white juice, but mixed with a few berries, which had coloured juice like the male parent Le Teinturier. The seeds of these berries were carefully set apart and sowed, and after seven years one of the young vines which came from the seed of an Aramon when grafted on a vigorous stock yielded fruit, with the coloured juice of Le Teinturier. Other. plants fruited the next year, and amongst them one which yielded fine and abundant fruit, with the requisite character of coloured juice ; this was chosen for pro- pagation, and ultimately many acres of the variety were set out with grafted plants. Such was the result of the experiments of our author’s father. The son in his turn took up the subject with similar results. The process of grafting enabled him to obtain fruit at an earlier period than he would have been able to do had he waited for the result in the simple course of nature. Ten years or more in general pass by before fruit is obtained, whereas M. Bouschet reduced the time to five or six. . The most important point, however, in a scientific point of view, which resulted from the experiments was the effect of cross- ing on the fruit the first year. The berries which were fertilized with the pollen of Le Teinturier yielded coloured juice, while VINEYARD CULTURE IN FRANCE. 51 others on the same bunch retained their original character. It is generally supposed that the effect of crossing is confined to the embryo of the seed which has received an impression from the strange pollen. It has indeed been asserted that the colour of the seeds of peas and kidney beans has been immediately modified the first year by crossing ; but Mr. Darwin, after a careful ex- amination of the point, did not find the supposition confirmed ; so that the facts related by M. Bouschet are without parallel. Amongst the numerous varieties which he has raised, it is stated that some are so early as to make it always possible to have the vintage in the South of France in August. The wine, too, which they produce is of excellent quality, and in consequence obtained the Silver Medal at Avignon in 1858. XIII. Vineyard Culture in France. By the Rev. M. J. Berxetny, M.A., F.LS. THE source from which our information on this subject is derived, is the Comte Odart’s ‘Manual of the Vine Dresser’ *, a small volume, but containing a vast mass of information. We shall, however, confine ourselves to that part of it which more immedi- ately concerns the objects of the Royal Horticultural Society, entirely neglecting all that relates to the mode of preparing or preserving wine. The intelligent gardener may perhaps be able to pick up a few useful hints, though he will now and then be surprised at practices which contradict his preconceived notions, and which he could not perhaps copy in his more limited area without almost certain loss of credit, if not of produce. ) It is not necessary to dwell on the particular varieties of vine which are grown in different districts, the choice of which some- times depends upon caprice, but frequently on the necessities of particular soil, climate, and aspect, or of the requirements of the special kind of wine which it is the vine-grower’s object to produce, or for which his vineyard is best calculated. It may, however, be observed that, with very few exceptions, notwithstanding the well- known fact that they are almost if not entirely exempt from the mildew which has been so disastrous for nearly twenty years, he avoids the American grapes, which belong to an entirely different species of the genus Vitis. The greater part of them have a foxy ~ * Manuel de Vigneron, 8vo, pp. 358, Troisiéme édition, E 2 52 ROYAL WORTICULTURAL SOCIETY. taste, which does not suit the European palate. Some two or three, however, are cultivated ; and perhaps amongst these the Isabelle is the greatest favourite, which yields a grateful wine remarkable for a taste resembling that of raspberries. It was indeed proposed a few years since to send over some well-informed person to the United States, to examine on the spot the particular varieties which afford the best American wines, some of which command a price almost equal to that of Lafitte or Chateau Margout; but, not- withstanding their exemption from the mildew, it was thought that the prospect of producing first-rate wine from them in Europe was so small that it was not worth while making the ex- periment. And there is the less reason for doing it, as the French vine-dresser is now in a great measure master of the disease, by a proper application of the sulphur treatment. He at least, whatever may be the cause, has been too wise to follow the example of Madeira, and root up his vines in despair. The circumstances under which vines are grown in England are so different from those of the vineyard, that we can scarcely hope to learn much from a consideration of the climatic conditions which affect the vine-growers in France. He has greater extremes of temperature to contend against ; the young shoots of his vines are often cut off by severe frost, a circumstance which very rarely happens to us even in open-air culture; and, according to the degree of moisture in the air, especially if there be a high state of the hygrometer combined with a great degree of heat, his grapes will mould and become useless. As in every other branch of cultivation, where particular plants have been subjected to very different modes of treatment and climate, the varieties are ex- tremely numerous,and experience has shown which are best adapted to the purposes of the cultivator. In our grape-culture, where the number of varieties is more restricted, I have often thought that sufficient attention is not paid to the selection of the kinds which suit the situation best; and in consequence where one never fails, others are always complaining of some disaster or other, during the whole period of growth, from the first pushing of the buds to the gathering of the last gleaning-grapes. The mode of cultiva- tion may be the same, but yet from local circumstances the result may be very different. Nothing perhaps so greatly affects the quality of the produce as the soil. Thence it is that the principal part of the nourish- ment is derived; and even supposing it to contain nothing dele- terious, the necessary constituents will be taken up in such differ-— VINEYARD CULTURE IN FRANCE. 53 ent proportions as greatly to affect the chemical condition of the sap, and consequently of the produce. It would scarcely be pos- sible to meet with two plots of any extent where the soil is pre- cisely the same, but it is found that, provided the situation and climate are suitable, but few are utterly unfit for cultivation, pro- vided the ground is well mixed with stones or gravel, the only points which it is necessary to avoid being extreme tenacity or light- ness. Ifthe constituents of the soil are bound together by tena- cious clay, which is easily beaten down by a shower, or, on the other _ hand, hardened by drought, it is what is called in France “ terre battante.”’ Such soil is also called cold, because the fruit arrives slowly at maturity. A rich and deep soil is not generally thought to be calculated for the vineyard, but rather for field culture. If, however, the soil is light, but not sandy, as is the case with that which produces the best Tokay, and if it effervesces violently when treated with acids, even though it may approach the term of extreme lightness, it may be considered an exception to the general rule. The soil which is best calculated for corn is seldom fit for the vineyard; while, on the contrary, the admixture of stones, and frequently the too great inclination, makes the best vine-ground unfit for corn. It does not seem to matter greatly, as far as fertility is concerned, whether the stones are quartzose, calcareous, or ferruginous, though doubtless the peculiar nature of the soil and its constituents may make a great difference in the character of the produce. It is believed, for instance, that the wines of the Cote-d’Or owe their beautiful ruby tint and sweet- ness to the ferruginous nature of the soil, while some white clays are equally famed for the white wines. In a few instances good wine is obtained from sandy soils, but the produce is in general small; where, however, the texture is extremely coarse, as in land which is called “graves sables’’ at Bordeaux, the vine succeeds perfectly, and the produce is sometimes first-rate. It is not only a mistake to clear the ground entirely of stones, though for various reasons it may be well to remove those which are of such a size as to interfere with culture, but it is absolutely necessary 2 some cases to introduce them, where they are not already present. Even in some corn-land in our own country, fertility is greatly impaired if the stones are entirely removed, as they always retain a good deal of moisture,and the plants find it to their interest to cling to them by their rootlets as a certain refuge in time of drought. As regards site and aspect, neither a narrow valley nor an ex- 54 ROYAL HORTICULTURAL SOCIETY. posed hill are fit for vines ; in the former case the grapes are apt to rot before they arrive at maturity, and in the latter the skin hardens in consequence of exposure to the air, and the berries never arrive at their full perfection,—facts which may teach our artificial cultivators to account for a good deal of the spot and rust about which they complain so bitterly. It seems certain that many of the best wines follow the course of rivers, and that the quality becomes inferior in proportion as the vineyards become more distant. It is said, too, that they are more subject to frost, a circumstance which is contrary to the experience of our own country ; for in the same parish, within two hundred yards, fruit- trees are often materially impaired by frost on the low ground near a stream, while with the difference of some twenty feet or more of elevation they are safe. Our author is content with stating the fact very decidedly, confirming the statement by various in- stances, without, however, attempting any explanation. It seems almost self-evident that a southern aspect must in gene- ral be most favourable to vines, and, indeed, is the only one in which they can be expected to do well in our own country; but there are many examples of valuable vineyards which have a northern exposure, which is indeed preferred for some vines. In such a situation they are less injured by spring frosts; and there is a prejudice in favour of some beneficial influence of north winds, in addition to their power of drying soil which is too moist, and dis- pelling general humidity. Amongst the various methods of propagating the vine, none seems more efficacious than grafting, a method which may be em- ployed advantageously in our artificial cultivation, where the va- rieties under cultivation are not suited to the situation or where the produce is bad, provided the roots are in a proper soil and in a healthy condition. It is extensively practised in France, and is a very ready method in cultivation, on a large scale, of altering in avery short time the character of a vineyard. Added to which the produce from recent cuttings is always at first inferior, whereas the full perfection of the variety is at once attained by grafting, while the old stools seem frequently to acquire fresh vigour from the young blood. Omitting the whole of the chapter which treats of the different modes of cultivation employed in different countries, I pass to that of manures, which is of more immediate interest. I¢ is well known that for the more delicate wines coarse manures are avoided as much as possible, though they are useful enough where VINEYARD CULTURE IN FRANCH, 55 the object is to secure an enormous crop of grapes for the manu- facture of brandy. The experience of different countries in this respect, indeed, is different. Mr. Mumm, so celebrated for his Rudesheimer, informed me that in many vineyards on the Rhine large quantities of manure are employed ; but this practice, though suitable for Germany, might be extremely prejudicial in Southern France or Spain. In our own country, where it was once the fashion to bury putrid animals and other abominations in the ground prepared for vines, the voice of almost every experienced cultivator is now raised against the disgusting practice. Nothing is so much deprecated in the vineyard as a soil which sets hard after the first heavy rain, a point which is sometimes neglected in garden practice. Something must be done to alter the texture; and where lime does not exist in the soil already, a dressing of marl, or of a compost made with alternate layers of quicklime and stable-manure, may be employed with advantage, while in some cases, where lime is already present, an addition of sand will be sufficient. The manure must, however, be in very thin layers, as a large proportion would confessedly be injurious. Our author gives some directions towards the determination of the chemical nature of the soil from the natural vegetation ; but if the matter were of any importance to us as vine-cultivators, the information would fail of its proper effect, since the plants he mentions are by no means so certainly indicative of the absence or presence of calcareous substances as he supposes. Marl is said to be an effective remedy against a tendency to decay, from which our cultivators often suffer so severely. Herbaceous vegetables are next recommended, either sown in the vineyards and ploughed in, as lupines, rye, or tares, or col- lected in marshes, as reeds mixed with Potamogeton, and buried. in the soil so deeply that the plough cannot reach. The reed de- cays very slowly, and the effect, therefore, is only gradually pro- duced, and is carried on for some years. Sometimes these and other aquatic plants are cut up into a kind of chaff, and used after the fashion of mulching. The truly aquatic weeds, such as Pota- mogeton, contain an enormous quantity of water, and when de- cayed leave a very small residuum ; but they abound in animal matter, as the eggs of Mollusca and the animals themselves, and in consequence are not a bad manure for general purposes, though they contract so much, that, as I know from experience, they hardly pay the cost of carriage. A practice, however, prevails in many vineyards, and one which 56 ROYAL HORTICULTURAL SOCIETY. is highly approved, though it would surprise many of our grape- erowers, viz. of burying in the ground branches of shrubs, such as heath, broom, cistus, juniper, and box, especially the latter, which is said to give out during decay a larger proportion of azote than — any other vegetable. The danger in my own apprehension would be of infection from fungus-spawn developed on the decaying branches ; and I suspect that mischief sometimes arises from this cause, which is attributed to other circumstances which are in all probability harmless. Seaweed is sometimes used on the coast, but is said to communicate a very unpleasant flavour to the wine. The prunings or thinnings of the vines themselves, again, are often used with good effect,—a practice similar to that which prevails in some of our best hop-grounds, where no manure is used in soils abounding with phosphates, except the old plants cut up into chaff. Burnt earth, especially when mixed with lime-rubbish from old buildings, appears to be an excellent dressing, and is said to in- crease greatly the strength of the wine, while plaster mixed with dung seems to have a very powerful effect in producing vigorous shoots. As for animal substances, such as horns, raspings of hoofs, bones, &c., if used at all, they should be used with caution, as the grapes sometimes become perfectly detestable after an overdose. As regards what may be called purely chemical or artificial ma- nures, our author, who sets his face against everything in the shape of chemistry, gives us little or no information. There is a great deal of information upon other matters in the volume, but I have selected those only which are likely to be suggestive. There is certainly great room for improvement in our erape-culture, notwithstanding the perfection at which we have arrived in some of our best establishments. What is wanted in many of our cultivators is a thorough knowledge of the principles of cultivation, and a power of adapting these to peculiar circum- stances. A great deal of the unhealthiness of our vines, of the failure or blindness of the flowers, of the early decay of the fruit, of intense rust, and other misfortunes might be avoided, and we should not see remedies for vine-mildew applied where no mildew exists, or half-a-dozen nostrums employed, one of which is. quite sufficient to induce mischief. Above all, we should not have arti- ficial manures applied of the composition of which the cultivator has no knowledge; and if their market-price bears no proportion to their real fertilizig powers, the mere loss of money is a trifle, compared with the fact that they may contain an overwhelming proportion of sulphate of iron or some other chemical which is WICHURA ON HYBRIDS. BT positively injurious, as I know to have been the case in one instance which has come before me. XIV. Abstract of Max Wichura’s Observations on Hybridi- zation*, By the Rey. M. J. Berxeney, M.A., E.LS. In the former series of this Journal I gave an abstract of Geert- -ner’s important work on vegetable hybrids; and a translation of Naudin’s more recent observations appears in the present volume of the New Series, together with some interesting remarks of M. Decaisne’s on the effects of intercrossing amongst different va- rieties of pears. Very recently a most instructive memoir ap- peared at Breslau, by Max Wichura, which contains so much weighty matter that a copious abstract cannot fail to be acceptable to our readers. Jam indebted to Mr. Darwin for the loan of the book, and have profited by his marginal notes pointing out the principal points of interest. Herr Wichura informs us in his preface that he was led to the subject by the fact of his friend Dr. Wimmer having arrived at the conclusion, from numerous observations, that a great part of the doubtful forms in the difficult genus Salix were hybrids. From a desire to confirm the correctness of this conclusion, of which he was, however, already convinced, he determined to in- stitute a series of experiments with a view to find out what would be the actual results of artificial impregnation in this perplexing genus. ‘These experiments were commenced in 1852, and con- tinued uninterruptedly till 1858; but unfortunately, partly from illness and partly from a long absence in Japan, they were dis- continued, and as there seems no probability of their being re- sumed, he has thought it best to publish at once the results of his experiments, comparing them, where requisite, with those of Keelreuter and Gertner, and pointing out their connexion with Darwin’s views on the origin of species. In all experiments on hybridization, the one great desideratum ig to exclude the possibility of access of every kind of pollen ex- cept that which is the subject of experiment. As willows have a singular propensity to form hybrids, and are, at the same time, * Die Bastardbefruchtung im Pflanzenreich, erlautert an den Bastarden der Weiden: von Max Wichura. Mit zwei. Tafeln. 4to. Breslau, 1865. 58 ROYAL HORTICULTURAL SOCIETY. dicecious, a circumstance which obviates all difficulties about doubtful extirpation of anthers in the female parent, they are peculiarly fitted for the purpose, and as their pollen is so heavy that it falls at once to the ground when ripe, instead of floating in the air, and is, moreover, covered with a raised delicate network, it is peculiarly adapted to adhere to the hairs of insects, without whose help it scarcely ever reaches the female plant, which is often at a great distance from the male. Multitudes of insects, however, greedily search out the blossoms of either sex, and in consequence impregnation seldom fails in wild plants. | In this appetency for the flowers, it is of the greater importance in the course of experiments to find some effectual way of pre- venting the access of insects. or this purpose cylinders were made of thin tarlatan, 2-3 inches wide, and 6-12 inches long, furnished with a string at either end to tie them closely to the branches, and strengthened in the centre with two or three bands to prevent them collapsing. To show that the insulation was per- fect some flowers were left to themselves; and not a capsule set. In the case of those flowers which were artificially impregnated, so soon as the stigma dried and the ovary began to swell, the cylinders were removed as no longer necessary, and replaced when the seed was nearly ripe, to prevent its being carried away by the wind. The spikes having the male blossoms, moreover, were sepa- ‘rated as soon as the anthers began to burst, and placed in water to prevent the access of insects. The pollen was applied with a camel’s-hair pencil, and a separate pencil used for each kind of pollen, which was always taken from the same individual and, as nearly as possible, normal plant. For the impregnation of early flowering species with those which blow later in the season, the fact was of great importance that the pollen of willows retains its potency for some time. In some cases pollen ten days old was efficient, while the vitality was still further prolonged by steeping it in a solution of honey, made of as much as will lie on the point of a knife, mixed with two ounces of water. ‘Fresh pollen, placed in this mixture, fre- quently began, in the course of ten or twelve minutes, to put forth its tubes. Pollen of Salix silesiaca, eight days old, seemed almost as potent as ever; in twenty-eight days the traces of vitality were very slight, while that of Salia cinerea had become weak in sixteen days, though still capable, after immersion for three hours, of slowly developing its tubes. On the whole it should seem that pollen kept in a dry, cool, shady place,’ may, WICHURA ON HYBRIDS. 59 under favourable circumstances, be still efficient after fourteen days, while that eight days old may be trusted implicitly. The seeds of willows germinate very rapidly, and lose their vitality with proportional rapidity. The pollen-grains, indeed, sometimes preserve their vitality longer than the seed. This quickness of germination arises from the fact that the embryo is already richly supplied with chlorophyll, and that the testa is very thin and transparent, while there is not a trace of albumen. They soon dry up if they are not in contact with moist earth; they should therefore be sown as soon as they are ripe, and in from twelve to twenty-four hours the cotyledons make their appearance. Care must be taken not to water the young plants too heavily, or the delicate seedlings may be washed away. Our author’s plan was to raise the plants in pots, which could be supplied with water from below, and easily protected from the access of any strange seed. They were allowed to remain in this situation till they were some inches high, and then transplanted into the open air; and thus plants sown in May obtained a height of two or three feet by the end of summer. The smaller kinds generally flowered in three years, the larger, but not arboreous species, in about four. Scattered catkins, however, sometimes appeared on two-year-old plants, and in one instance a plant sown in June produced flowers when ten months old. Our author adds a remark on the use which he made of natural hybrid willows during the course of his experiments. They seemed to be of the greatest importance as regards hybrids com- posed of more than two factors. By their help he was enabled to raise two hybrids (of which admirable nature-printed figures are given at the end of the volume) compounded of six different spe- cies, which he believes, after seven years’ experience, to have been impossible with artificial hybrids. An example is added of the composition of hybrids of more than two species, the parents being a spontaneous hybrid of S. Lap- ponum and WS. silesiaca, a spontaneous hybrid of 8. purpurea and S. viminalis, with an artificial hybrid of 8. caprea and 8. daphnoides. The circles in the following scheme indicate the male, the squares the female, and the triangles the father and mother plants of the free hybrids or species indifferently. 60 ROYAL HORTICULTURAL SOCIETY. S.Lapponum. silesiaca. purpurea. viminalis. caprea. caprea. daphnoides. daphnoides, ue ee A oe A ye Li A To eas eee On Oa His notation to exhibit the whole history of the hybrid is ex- pressed thus, 2 indicating female, ¢ male, spont. spontaneous, art. artificial 2 8. (2 C2 (Lapponum + silesiaca) spont.+ 3 (purpurea+ vimi- nalis) spont. +(o 2 caprea+ $ daphnoides) art.), which, expressed at length, denotes that the senary hybrid was raised between a female parent derived from the intercrossing of two spontaneous hybrids, of which the female parent was derived from S. Lapponum and silesiaca, and the male from 8. purpurea and viminalis; while the male parent was derived from an arti- ficial cross of S. caprea impregnated with the pollen of S. daph- noides. In the names of artificial hybrids, the female parent always comes first, while in spontaneous hybrids the parents are placed in alphabetical order. A complete list of the author’s experiments follows, giving in one column an account of those which proved successful, and in another those which did not succeed, with the date of the ex- periments. The former, comprising binary, ternary, quaternary, quinary, and senary hybrids, amount to thirty-five ; the unsuccess- ful, amounting to eighty-one, include the three first heads; no unsuccessful experiments were made in the fifth and sixth; but an attempt to obtain an octonary with two quaternary hybrids did not succeed. Both lists are well worth the study of every one engaged in the scientific determination of willows. The propor- tion of successful experiments is far more unfavourable in binary than in more complicated combinations. Nothing, however, can be concluded from this; for in binary hybrids an endeavour was made to effect heterogeneous combination, or certain unions already existing in free nature, and that with old pollen, while in WICHURA ON HYBRIDS. GL complicated combinations the object was to combine as many species as possible; the species, thereforé, most nearly related to each other were chosen, and fresh pollen was used. It is not to be doubted, moreover, that the more favourable results amongst complicated hybrids depended on the more favourable circum- stance selected for their production ; besides, it should seem that willows have a great tendency towards the production of compli- cated hybrids, which must be regarded as a very peculiar circum- stance. Exceptional cases doubtless often depend upon unfavour- able accidents ; for combinations which failed one year succeeded the next, and it is only after a large continuous series of observa- tions that we can arrive at any perfectly satisfactory result. Wichura does not consider it necessary to repeat in willows the experiments of Kelreuter, Gertner, and others, which show that plants have a superior appetency for their own pollen to that of any other species. This depends probably on the circumstance that the strange pollen does not push forth the pollen-tube so rapidly as that which is native, so that if both kinds of pollen are applied to- gether, the tube of the strange pollen, supposing it to be properly protruded, finds the micropyle occupied on its arrival. Gertner informs us that in different plants a different number of genera- tions must pass by to secure the conversion of one species into another. In willows, it appears from Wichura’s experiment that it requires only four years. A small-leaved form of S. (purpurea + viminalis) was used for this experiment, which was continued for two generations. A fe- ~ male hybrid between 8. purpurea and viminalis was impregnated by S. viminalis, the result of which was a hybrid scarcely distin- guishable from 8. viminalis. Again, a female hybrid, the result of a hybrid between S. purpurea and viminalis, impregnated by SV. viminalis, impregnated in its turn with S. viminalis, produced a hybrid still more near S. viminalis, and a further crossing would in all probability have perfected the change. It was a matter of interest to observe how far the peculiar smallness of the leaves would be recognizable in the result of the first-mentioned experi- ment. This was distinctly the case, and it seems clear that the propagation of individual peculiarity may be effected in a hybrid. A hybrid fertilized with its own pollen produces plants the same as or resembling both the parents. The peculiarities of the parents are moreover repeated in the hybrid. Quaternary hybrids fertilized with their own pollen, produced seed which germinated, but the young plants soon failed. 62 BOYAL HORTICULTURAL SOCIETY. Gertner believed that in such combinations, amongst many individuals resembling the hybrid, some plants would occur which reverted very nearly to the maternal, or less frequently to the paternal type. No such reversions, however, occurred in the course of Wichura’s experiments. Particular individuals showed indeed many variations, but no reversion. He believed, therefore, that the pollen of either parent must have had access without Gertner’s knowledge; and Mr. Darwin thinks it probable that the instances alleged by Naudin were due to the circumstance of his plants being cultivated. Wichura had no opportunity of exa- mining the truth of the fact asserted by both Kelreuter and Gertner, that hybrids prefer the pollen of one of the parents to their own, or that the pollen of some strange species may make the pollen of the hybrid powerless, though he thinks both state- ments quite probable. He remarks, moreover, that his quinary and senary hybrids are quite new in the history of hybridization. He believes that the possibility of still higher combination is only prevented by the constantly increasing sterility of the produce. The senary hybrid whose formula is given above was still so fruitful that it would scarcely refuse union with an heterogene- ously combined senary, ternary or quaternary hybrid, while the other senary hybrid, between a quaternary of Salia Lapponwm and silesiaca [] and purpurea, viminalis CO, and fertilized with an arti- ficial hybrid of caprea [] and daphnoides ©, and then finally fer- tilized with pure daphnoides ©, did not give an opportunity of carrying the experiment further, inasmuch as all the plants pe- | rished before they produced flowers. Impregnation between two quaternaries failed as stated above, in consequence of the far advanced sterility of the female plant. He doubts, moreover, whether it is possible to raise a hybrid of the sixteenth degree between two octonaries. He has nothing to say as regard willows in confirmation of Gertner’s remark, that while species will not combine with some other species, they will do so with a hybrid of that species, as, for example, Nicotiana glutinosa, Tabacum, and Langsdorfii, will not combine with WV. rustica, though they will do so with a hybrid of WV. paniculata and rustica. ‘We now come to a very important chapter on the imperfect nature of hybrids. Our author divided his experiments into two series, successful and unsuccessful. There are, he says, certain degrees of success, which, however, cannot be used as the stepping- stones for a new division, since they pass into each other, WICHURA ON HYBRIDS. 63 but deserve mention as characteristic phenomena in hybri- dization. The following degrees of failure may be noted :— 1. The catkins submitted to hybridization wither as soon as the flowering is complete, like those which have not been impregnated, and fall off. 2. The ovaries swell and ripen, but do not contain a trace of seed. 3. The ovaries are quite filled with the silky hairs which clothe the umbilical end of the seed, but contain no embryo. 4. Seeds are present, but small, languid, and incapable of ger- mination. 5. Seeds apparently perfectly developed, but do not germinate. 6. Seeds germinate, but the young plants are weak and wither in a short time without further development. The gradation in the number of seeds next demands our notice. The results of different experiments were very various. Sometimes the seeds were few, but fertile and active ; sometimes, on the con- trary, numerous, but with only a few fertile mixed with a number of abortive seeds; sometimes tolerably numerous, without any such admixture; but in general hybrids yielded on the whole a smaller number of seeds than plants impregnated with their own pollen. This imperfection depends on the nature of hybrids, which, according to our author, are never so active as pure plants—a position which is perhaps doubtful. This weakness he believes to arise from a comparative want of potency in the pollen, though hybrids often exhibit a peculiarly luxuriant but rank growth. It is not necessary to describe the structure of willow-pollen. It is sufficient to observe that in hybrid willows many modifica- tions occur. The imperfection of the pollen in hybrids is often adduced as a decidedly distinctive mark between them and pure species, but this is incorrect. ‘There are hybrids whose pollen is scarcely less regular than that of the parents, as for example in Petwnias, and there are pure species which have more irregular pollen than many hybrids. It is, however, true that in the greater number of cases the pollen of hybrids is less regular than that of pure plants. In willows this is a law without exception. Amongst pure species, only S. fragilis (though not the nearly allied S. alba) and single individuals of 8. triandra had a large number of irregular 64 ROYAL HORTICULTURAL SOCIETY. grains in their pollen. The pollen of all other European willows is remarkable for its great regularity. One grain is almost perfectly like another in size, colour, constitution, and form; and pure species are peculiarly distinguished by this character from hybrids, in whose pollen, amongst a greater or less number of large, regular grains, there are always some which areabnormal. Moreover the various hybrids differ greatly from each other in this respect. Hybrids whose pollen contains no perfectly developed grains, and hybrids which amongst normal pollen-grains contain only a small percentage of irregular grains, stand at the two extremities of a series which numbers almost as many intermediate links as there are hybrids. It may be asked of what nature is the irregu- larity of hybrid pollen? How do the differently formed grains comport themselves with respect to potency? How are they developed? In what relation do the different degrees of irregu- larity which we recognize in hybrids stand to their composition ? These irregularities are of six kinds. 1. Linear elongated bodies, about the size of an anther-cell, which contain within a membrane a large number of dark, dirty- yellow, round pollen-grains of somewhat more than the usual size. 2. Irregular bodies, consisting of from two to four full-grown grains, sometimes light, sometimes of a dark dirty yellow, which contain a great mass of oil. 3. Grains nearly twice the usual size, of a dark dirty yellow, scarcely transparent, otherwise of the regular orbicular form, and containing much oil. 4. Globular bodies, three, four, or ten times smaller than the normal grains, colourless and almost translucent. 5. Grains which differ only in a small increase or diminution of size from normal grains, with which, moreover, they agree in the pale colour, semitransparent aspect, and in the regular develop- ment into a ball when placed in watery fluids. 6. More or less regularly plicate, dark, impellucid bodies, of the normal size or smaller, which, placed in water, are unaltered and do not assume a spherical form. The last form is the most common, and exists in pure S. fragilis and triandra; 4 and 5 often occur together. No. 3 is uncommon, and 1 and 2 very rare. No. 1 has occurred only in a spontaneous hybrid between SN. cinerea and incana, and No. 2 only in a very few instances. Imperfections in the sexual organs of hybrids have, however, been shown by Geertnér and others to go further in other plants WICHURA ON HYBRIDS. 65 than amongst hybrid willows. But what most concerns us at present is the remark of Geertner, that in the anthers of all fertile hybrids, as for example in Micotiana rustica paniculata, Malva mauritiana sylvestris, Aquilegia atropurpurea canadensis, Lychnis diurna vespertina, larger and smaller grains are mixed in different proportions, besides small grains of different degrees of irregu- larity, as elongated, shrivelled, or mere arid sacs; and this is the case especially with those which are the least fertile, a fact which was observed also by Kelreuter. A tolerably correct opinion, therefore, may be formed of the comparative fertility of hybrids from an examination of the pollen, as appears also very distinctly from Wichura’s observations. Pollen-grains of willows were treated with the above-mentioned solution of honey; and it appeared, on microscopical examination, that the normally formed grains of hybrids, of a light colour and semitransparent aspect, constantly developed pollen-tubes ; those like No. 5 usually did so; the irregular grains like No. 2, if of a light colour, occasionally ; while the confluent grains, of a dark, dirty yellow hue, with those comprised under Nos. 1, 3, 4, and 6, never made pollen-tubes, and must be regarded as absolutely sterile. It appeared also, on comparing the activity of the pollen-grains of hybrids with those of pure species, that there was a difference. The defect in hybrid pollen in some hybrids, and probably in a great many, though not in all, was twofold. The number of tube- producing grains is far smaller than in pure species, while the potency of these grains is comparatively weak. The study of the pollen-grains in willows is comparatively easy, as the contents of the anthers in every stage are easily squeezed out on the stage of the microscope by the covering glass, so that they are ready for examination without any further preparation. Willow-branches, moreover, are readily developed in water, and the different stages of development of the pollen observed without much trouble. In pure willows the mother cells of the anthers are of equal size, and divide, with almost mathematical precision, into four tetrahedric pockets, in which the contents form yellowish shining pollen-grains of exactly the same size; while in hybrids the course of development is far less regular, and subject to the above-men- tioned derangements. | The first form arises from the fact that the component cells of the substance of the anthers (Collenchymzellen), contrary to the established rule, do not dissolve, but still hang together, and thus VORe1. F 66 ROYAL HORTICULTURAL SOCIETY. prevent the separation of the mother-cells. In mature anthers these confluent pollen-grains form yellow linear bodies; when pressed out of the immature anther they have an appearance like that of frog-spawn. The four next forms arise from an irregular division of the mother cells. In hybrids in which these forms occur, sometimes we find the mother cells only uniseptate, and in consequence two large pollen-grains are formed instead of four half the size. Some- times, though the cells are quadriseptate, the division is irregular, and one larger grain with three smaller ones is often the conse- quence. A further cause of irregularity arises from the fact that the dissepiments of the mother cells are so imperfect that the pollen-grains of the different component sacs are confluent with each other. In this way the compound grains of No. 2 arise, consisting of two or more confluent individuals. More rarely the cells divide into a larger number, from sixteen to twenty, and the grains are consequently minute. In No. 6 the division of the mother-cell is at first apparently normal, as are also the pollen- grains, and the malformation first appears when the pollen-grains begin to contract. The triple folding does not take place. One half of the globe remains conyex, the other is pushed in, so that a purse-like body is formed, or, if the triple folding takes place, it is very irregular. In either case, the dark colour and want of transparency show that the fluid contents of the grains are more or less deficient. : It is worthy of remark that the irregular division of the mother- cells does not necessarily induce sterility. On the contrary, the pollen-grains of a greater size than usual, which arise from the irregular division of the mother cell, are frequently fertile. Steri- lity attaches rather to those recklings which are below the normal size and which are generally colourless and transparent, to those which are not expanded when in contact with fluids, or, finally, to those which are extravagantly large and confluent, if of a dark brownish yellow. This change of colour depends probably upon some anomalous composition of the fluid contents. It is scarcely possible to classify hybrids according to this im- perfection of the pollen, because the gradations are so gentle; certain laws, however, seem to prevail. 1. The anomaly of the pollen increases with the succession of generations arising from the fertilizing of hybrids with their own pollen. This is the case with hybrid willows; and Gertner has shown that, with respect to hybrids of Agqwilegia, Dianthus, Lava- De ee ey WICHURA ON HYBRIDS. 67 tera, and Gtewm, there was a perpetual decrease of fertility and a general decrepitude, though he does expressly state that this de- pended on imperfection in the pollen. 2. Different individuals of the same hybrid generation nearly resemble each other in the degree of imperfection in the pollen. This was found to be the case in all experiments with artificial hybrids which for the most part yield a large number of male plants. In wild hybrids, especially of the formula 2 (2 (4+b)+ db (a+b)+ 3b (a+b), &e., it is very probable that individuals may be found in which the different degrees of imperfection of pollen may be found in one and the same hybrid. It is possible also that different individuals of the same two species, when hybridizing, may yield different kinds of irregular pollen. 3, Distantly related species of willow, when combined in hybri- dization, give a more irregular pollen than nearly allied species. 4, The anomaly of pollen increases with the number of inter- mingled species. 3 S.( 2 (Lapponum + silesiaca) spont.+ 3 (purpwrea+viminalis) spont.) has far more sterile grains than S. (purpurea+t viminalis) and S. (Lapponum-+silesiaca) spont., which has proportionally regular pollen, while even some ternary hybrids are quite sterile though the parents are fertile. Again, the quinary 2 8. (2 (pur- purea+repens) + 3 aurita) art.+ (caprea+vuninalis) art.) has by far a greater number of sterile pollen-grains than all the binary hybrids which are known of its five parents. We now arrive at the female flowers of the hybrids ; but unfor- tunately this part of the subject has engaged Wichura’s attention much less than the former. It is indeed overwhelmed with diffi- culties, and would require immense patience to follow it out pro- perly ; for the contents of the embryo-sac could not be observed: so easily as those of the anthers. Professor Henslow went as far as could be expected in this direction when he wrote his model treatise on a hybrid Digitalis; but more is required to satisfy the existing state of science, and a thorough examination of any differences that may exist in the more intimate characters of the ovules in hybrid plants is one of our great desiderata. Wichura, however, remarks that the female sexual apparatus suffers in many cases a certain degree of imperfection. The ovaries of certain willows, which appear to be binary hybrids of S. viminalis, alba, and emerea with 8. triandra, or ternary hybrids of S. viminalis, caprea, and cinerea, are perfectly sterile. They F2 68 ROYAL HORTICULTURAL SOCIETY. do not show the slightest trace of any development of the seed though abundant opportunity was afforded, either iv the way of _ artificial application, or through the natural agency of insects in the open air. The female catkins of the above-mentioned hybrids of S. triandra wither quickly after expansion, and fall off prema- turely, those of S. longifolia, on the contrary, are apparently luxuriant, ripen and burst, but they contain no seed. As the male plants of S. (riandra+viminalis) and S. longifolia are dis- tinguished by a far advanced irregularity of pollen, a certain connexion between the imperfect formation of the male and female organs of this hybrid is not to be mistaken. Other examples might be adduced. In the greater number, indeed, of female hybrids of willows there is, in comparison with the pure species, a less degree of fertility, which appears only in the diminished number of seeds ; while many hybrid willows,examined superficially appear to be quite as fruitful, if attention is paid only to the woolly contents of the capsules. Even in these, Wichura believes that an attentive examination would show a diminished number in confirmation of Gertner’s assertion “that even the most fruitful hybrids yield constantly a smaller number of seeds than the parent species fertilized with their own pollen.” But not only in the organs of reproduction, but also in their vegetation, hybrids exhibit many phenomena by which they are more or less decidedly distinguished from pure species. Keel- reuter and Gertner both agree that the greater number of the hybrids which they raised artificially were distinguished by rank- ness of growth. ‘The plants were taller than their parents, spread more on every side, had a longer duration (being biennial or perennial when the parents were annual or biennial), were more capable of withstanding cold, and blossomed more freely, luxu- riantly, and precociously than the parents; something of which appears also from Naudin’s experiments, so far as extreme luxu- riance is concerned, as witness his hybrid Mirabilis. On the con- trary, Gertner speaks of other hybrids which succeeded only in very favourable weather, and were intolerant of cold. These were hybrids whose parents were only slightly related, and whose seedlings were delicate from the first. Similar examples occur amongst hybrid willows; but luxuriant growth is by no means the normal character. “It is doubtful whether the hybrids of S. caprea and viminalis, S. cinerea and incana, with their tall and spreading habit, are to be reckoned as examples, since they are to be explained by the union of tendency WICHURA ON HYBRIDS, 69 to an arboreous habit in S. caprea and incana on the one side, and to a fruticose habit in S. viminalis and cinerea on the other. The rank growth of the senary hybrid from 8S. viminalis, purpurea, Lapponum, silesiaca, caprea, daphnoides was indeed very striking ; and in this case, at the age of ten months a single catkin was produced—a circumstance which agrees with Gertner’s instances of the early blossoming of hybrids. Traces of a defective feeble development are far more frequent amongst willow hybrids than rankness of growth. 8S. (Q arbus- cula+ S purpurea) art.,a union it is to be observed of distantly related species, put forth every year a strong shoot, which, how- ever, in the course of the summer began to wither. Not one of the numerous plants which were raised from the intercrossing came into blossom, and all gradually perished. A senary hybrid im- pregnated with the pollen of one of its parents afforded a quan- tity of plants. Three of these, 63 years old, had attained a height of six feet, forming miserable little trees. Buds were formed every autumn which promised well for the following spring, but the wood did not get ripe enough to give strong shoots, so that they always remained weak ; and though they had the best place in the garden, they never produced any blossoms; and the result even of a hot summer was the same. S. ( 2 viminalis+ & daphnoi- des) art., in itself a tolerably strong hybrid, hada rather unfavour- able place near the garden fence. Of fifteen plants, eight were alive on Wichura’s return from his travels, and all of these sickly. A plant of pure S. viminalis, which had sprung up with the hybrids, and had the same difficulties to contend against, was healthy, a proof of its steady enduring nature. S.( 2 caprea+ ¢& daphnoides) art. grew vigorously to a height of from ten to twelve feet, but, though planted in a favourable spot, gradually failed, so that out of six original examples only one was left. S.C 2 ( 2 (Lapponum + silesiaca) + 3 (purpurea+ viminalis)) + 3 druinosa) art. was from the first weak and miserable, and all the specimens were overgrown by other stronger hybrids. Fries remarks of S. rubra, that is S. (purpurea+viminalis), Wimm., that in Sweden all the branches freeze, while this is not the case with S. purpurea or 8. viminalis. He concludes, therefore, in contra- distinction to Wimmer, that it cannot be a hybrid. Wichura proved that it is so by actual experiment. ‘The circumstance, therefore, mentioned by Fries is exactly applicable to what has been said of the comparatively feeble nature of hybrids, and is so much the more interesting since S. (purpurea+viminalis), 70 ROYAL HORTICULTURAL SOCLETY. Wimm., independent of the imperfection of the pollen, exhibits no symptoms of weakness in its outward appearance. The pos- sibility must therefore be allowed that the vegetative growth of other seemingly strong hybrids (as, for example, by far the greater number of hybrid willows) is essentially weak, so as to prevent them in the Darwinian struggle for life from competing with their parent species. If all these circumstances are combined with the imperfection of the pollen and the partial sterility of the ovaries, the com- parative defect of vital energy in hybrids may be considered as proved. Nor does the luxuriant growth of some contradict this, as we know that it often accompanies suppressed fertility. Keel- reuter’s views seem then to be confirmed, that the luxuriance of hybrids arises from sterility. The most fruitful hybrids are always less so than their parents. The weakness of the genera- tive organs in very luxuriant hybrids induces an increase of vegetative growth, while this is not the case in others which are too weak to exercise such a reaction. The relation of the sexes is modified in hybrids. The propor- tion between the male and female plants is different from what it 1s in pure species. This indeed requires further proof, the confined limits of his garden not allowing the author to make as many experiments as he otherwise would have done with pure species. His observations were therefore confined to the propor- tions which exist respecting hybrid willows in free nature, where the difference in the proportion of the sexes in hybrid and pure species is very striking. Pure species, however, are not quite equal in the number of their male and female plants. S. fra- gilis, alba, pentandra, and triandra, which are so strikingly distin- guished from other European willows by the double nectary of their male blossoms, bear, at least in the neighbourhood of Breslau, a greater number by far of male individuals than the species with a single nectary, as S. cinerea, viminalis, purpurea, repens, &e. In the former the males are more numerous than the females, in the latter this is not the case.- Males and females are in nearly equal proportions in these, though with a slight preponderance of females, while in the other the females are far more numerous. In arti- ficial hybrids with one nectary, there are about ten females to one male; but when more than two species are combined, it should seem that there are great differences ; but observations are at present not sufficiently numerous to establish any decided law. Wichura considers his observations on this matter to be quite ee ee ee ee ee et ee es WICHURA ON HYBRIDS. | 71 isolated, and not apparently to agree with those of Girou de Buza- reingues on the proportion of male and female individuals in Cannabis sativa, Rosé cinnamomea, Rumex acetosella, Spinacia ole- racea, and Lychnis dioica. Since willows have no petals, they will teach us nothing re- specting the different variations of colour which are so striking in many hybrids. We must therefore look rather to the different forms which they assume. When we consider the form of a hybrid with reference to that of its ancestor, we must distinguish three categories of characters. 1, Constant characters in which the parent species agree. These enter unaltered into the hybrid. 2. Constant characters in which the parent species are distin- guished from each other. These enter only by halves into a hybrid, so that it is intermediate between them. 3. Variable characters. In these the hybrid is equally variable. If the parents agree with each other in their variable characters, these are not necessarily inherited by the hybrid; and if they differ in their variable characters, the hybrid is not always inter- mediate. As regards the first and second, the following may serve as an example. S. pwrpwrea has two stamens whose threads and anthers are so intimately united that they seem to have only one thread and a four-celledanther. The stamensinthe other European willows are free, S. ncana only being exceptional, in which the threads are united halfway up. Ifa hybrid is formed between S. purpurea and another willow, the threads are confluent below in accordance with the first rule, while they are free above and divergent. S. purpurea, moreover, has sessile stigmas. The style of other species, as for instance S. viminalis, is rather long. The hybrid has the style about half as long as that of the second species. Similar examples may be adduced as to the position of the stigma, the leaves, the pubescence, the rough under surface of the leaves, the bark, the stature, the time of blooming, and finally the quan- tity of salicin in the bark. Wichura has seen only a single excep- tion to this law in NS. (2 arbusecula+ S purpurea) art. As regards foliage, it was exactly intermediate; but it had nothing in com- mon with the upright habit of 8. purpurea, but rather lay com- pletely prostrate on the ground, being in this respect an exagge- ration of S. arbuscula. It is possible, however, that this was only a sign of the weakness inherent in hybrids, and so the exception is only apparent. More complicated hybrids exhibit the same law, 72 ROYAL HORTICULTURAL SOCIETY. but it is of course more difficult to indicate the points of resem- blance and difference. Gertner indeed supposes that in genera which are rich in species, there are some which have a prepotent influence when hybridizing, so that in some hybrids the type either of the male or female parent prevails. Amongst the various hybrid willows, though the genus is so rich in species and so prone to hybridizing, Wichura has never seen a prepotent type, and doubts Gzertner’s statement, especially as he makes it in very qualified terms. With respect to the critical examination of types—whether, for example, a hybrid is more like the mother or father—the perfect distinction is subject in many cases to great difficulties, since very much depends on the subjective view of the observation; for in consequence of the frequent intermelting of both characters, the one observer finds in a hybrid the maternal type, while another thinks the paternal type prevalent. The question is of more importance whether the paternal or the maternal parent has most influence on the form of the hybrid. Gertner has made many experiments in this direction, and says, “The most important and interesting phenomenon in the inter- crossing of plants is the perfect equality of either production ; seeds arising from the impregnation of either parent produce plants of the most complete resemblance; so that the different origin, on the most careful examination of either kind of hybrid in respect of formation and type, does not induce the slightest difference.’ Slight differences were said to occur in the genus Digitalis only, but itis doubtful whether these depend on inter- crossing or on some other conditions. S.( 9 caprea+ 3 viminalis) and S8.( 2 viminalis+ 3 caprea) did not present the slightest differ- ence in the number of normal pollen-grains or in their outer form, but their resemblance was so perfect that they might be taken for products of one and the same crossing. Since the variable characters of species maintain their pecu- liarity as such in their progeny, a wide margin is left for the for- mation of varieties in hybrids which comprise the variable charac- ters of two species, notwithstanding the law of intermediation. The most remarkable examples are afforded by those hybrids which exhibit the prevailing characters in different parts of the same individual. The occurrence of such types is placed beyond doubt by such productions as Oytisus Adami, a hybrid of C. Labur- num and purpureus *. Mixed types are, however, very rare, and nothing of the kind has ever occurred amongst willows. * It is very doubtful, however, whether this be a hybrid at all. It is believed WICHURA ON HYBRIDS. 73 Wichura confirms Gertner in the assertion that where hybrid pollen is used for the impregnation of simple or complicated hybrids, as also in pure species, there is a great predominance of individual forms, while hybrid ovules impregnated by the pollen of pure species, even in the most complicated combinations, give very uniform products. On the whole, our author’s experiments have far more generally exhibited variety of form in the produce where the pollen of hybrids, and, on the contrary, uniformity where the pollen of pure species was employed. We may therefore attribute to the pollen of hybrids a tendency to produce varieties, while, since the ovules of the same, if fertilized with pure pollen, yield as uniform produce as those of true species, there does not appear in general to be any inherent propensity in them to produce varieties. There is but one observation of Gertner’s which gives any sup- port to the assertion that the varieties from the ovules of hybrids with pure pollen may be more numerous than from those of pure species. Tolerably constant forms arose from a hybrid fertilized with the pollen ofthe male parent, if the female hybrid was fruitful, but variable forms if the productive powers were weak. This could not, however, depend upon the pollen, which in either case was the same, but on the incipient sterility of the female, which in- duced a malformation of the ovules; so that the rule that the product of hybrid pollen is more polymorphous than that of pure pollen remains unshaken. The circumstances which favour the spontaneous production of hybrids in willows, seem to be nearly the same as those which facilitate artificial intercrossing. Dicecious plants, which are sub- ject to fertilization by insects, must necessarily produce hybrids, if they comprise, like willows, a great number of nearly related species, which grow in company with each other, and which have the same or nearly the same time of flowering. Wimmer believes that there are thirty-four undoubtedly pure European species of willow, or perhaps thirty-five if 8. helvetica is not a hybrid. If, however, S. pedicellata, Desf. and S. arctica, Br., whose hybrids in the extreme southern and northern lati- tude of Europe have not yet been studied, be excluded, we have to be an accidental variety produced by grafting C. purpureus on C. Laburnum ; and it is conjectured that a portion of the cells of the one plant must have become so intimately connected with the cells of the other, that when cell- division took place part of the plant assumed the type of C. Laburnum, another of C. purpureus, while others were exactly intermediate between the two. 74, * ROYAL HORTICULTURAL SOCIETY. thirty-two species which may concur in the formation of hybrids. From these sixty-six indubitable binary hybrids are known which occur here and there mixed with their parent species. Of these a complete list is given, which deserves attentive study. Ternary hybrids also are said to occur in nature, of which nine are enu- merated ; but these must be considered doubtful unless repro- duced artificially. Hybrids are distinguished from pure species, as regards their occurrence, by certain peculiarities. They can only arise where the parent species are associated. This is especially observable with respect to widely distributed species hybridized by species of rare occurrence. The intermediate form of S. Lapponwm and. myrtilloides is peculiar to northern swamps, where both species grow together. The hybrid S. (awrita+myrtilloides) is confined to Silesia and the few places where S. myrtilloides grows. A second more important difference consists in the comparative number of individuals. 1. As plants prefer their own pollen to that of strange species, and willows often grow in groups, there is a much greater chance for the success of their own than of strange pollen, especially when the times of shedding of the pollen do not coincide. Hy- brids must therefore be comparatively rare*. 2. Hybrid willows are generally in a position for self-impreg- nation; and as this mduces a gradual decay of vitality, hybrids have not the same chance of propagation by seed as pure species. 3. Hybrids, however, take the pollen of the parent species more readily than their own. The male plants are rarer in hybrid willows than the female; the pollen, moreover, of hybrids, when fertile, contains a certain number of impotent grains. The hybrid therefore has a greater chance of being fertilized with parent pollen, and, as this process is repeated, it is more probable that the hybrid should revert to one of its parents than that it should be preserved unaltered for any considerable time. 4. The difficulty is scarcely less with the female hybrid. Some hybrids have perfectly sterile ovaries and cannot be propagated by seed; others produce only a few seeds; and even the most fruit- ful are not so fruitful as pure species. Here, then, is another sround fot hindrance of their diffusion. 5. Others, finally, are weak as regards vegetative power. If, * Wichura’s opening observations as to the peculiar facility for hybridizing in consequence of the agency of insects being requisite to carry the pollen to the females, often situated at a considerable distance, must be regarded as modifying this observation.—Ep. WICHURA ON HYBRIDS. 75 then, they grow in company with their parents, they are soon overgrown, and so gradually die out. From all these circumstances it is clear that spontaneous hy- brids must be rare. If we except those which, like hawkweed, sedges, or brambles, are propagated in certain localities by suckers, they are of rare occurrence. In Silesia perhaps there is one hybrid amongst 500 individuals. There is perhaps of S. (alba+ fragilis) one per cent. of the parent species, 3 per cent. of S. (pur- purea+viminalis), + of S.(aurita+repens), 7, of S.(purpurea+ re- pens), 15 of S. (cinerea+ purpurea), =z of S.(triandra+ viminalis). These are, it is to be observed, only rough approximations. Com- plex hybrids are so rare that no estimate is made respecting them. In some confined localities, as in swampy wastes, sandbanks, river-beds, &c., certain hybrids sometimes grow together in con- siderable numbers. This is the case with S. (purpurea+ viminalis) on the Breslau river-banks, and with S. (aurita+repens) and SW. (purpurea+repens) in swamps, According to Andersson, S. (Lap- ponun+nyrtilloides) (S. versifolia, W abl.) surpasses its parents in number in some parts of Lapland. This depends probably on a little-noticed biological peculiarity in willows. They cannot bear being overshadowed, but become sickly, while the young plants perish, even amongst herbs of small stature. Moist places in districts bare of vegetation, either from artificial or natural circumstances, are the favourite places of the development of the light seeds. All therefore in a particular spot have vegetated in the same year; and so it may happen that, if these have come from some hybrid, the hybrids may surpass the pure parents in number. ‘In other spots of the same locality not a single hybrid can be found. Finally, hybrids have been widely cultivated in some districts by means of cuttings, as S. (alba+fragilis) and S. (fragilis + pen- tandra), which are used for enclosing the roads, and S. (pupureat+ viminalis) for basket-work. We pass over the systematic chapter, which, however excellent, is not especially suitable to the objects of this Journal. It is, however, remarkable that the great similarity between S. caprea, cinerea, and aurita is rather apparent than real. Though they do not absolutely refuse intercrossing, like the Cucurbita Pepo, maxima, melanosperma, and moschata, they comport themselves differently towards different species. Hybrids of these three species are by no means more frequent than other hybrids; and while many hybrids of S. caprea and awrita, with other uninectariferous wil- 76 -ROYAL HORTICULTURAL SOCIETY. lows, have a tolerably regular pollen, there is in hybrids of S. cinerea a marked irregularity which reaches its maximum in SV. (cinerea+incana). While S. caprea rather combines with S. vimi- nalis, Lapponum, and silesiaca, S. awrita does so with S. livida and repens, and S. cinerea,as S. incana and purpurea, seems to occupy a somewhat isolated position. We come now to the general conclusions. After first very briefly stating Mr. Darwin’s theory of the origin of species by variation and elimination, our author proceeds to some general consideration of hybrids. The habitual weakness, however, which he supposes in males is not universal, though perhaps in every male there is some weak point, however strong it may be in some particulars. The hybrid then comes with no new peculiarities into the world; it has those of its parents, and generally in a decidedly less complete degree. It is a perfect whole, so far as the peculiarities of the parents agree with each other; so far, however, as they differ it is intermediate, so that no speciality is completely reproduced; and since the differmg parts are com- bined in one intermediate whole, since these require different conditions, the hybrid can never be perfectly accommodated to outward circumstances*. A hybrid between a fish and a bird, were such a creature possible, would never either swim or fly well with its imperfect fins and feathers; and something of the kind must be the case with all males. We cannot, however, go so far with the author as to say that no hybrid can be exactly fitted for its place in nature, because, though it may not suit the circum- stances of either of its parents, its intermediate nature may be suited to some intermediate conditions, as species of different climates form hybrids. As no two parent species agree entirely with each other, though the hybrid may be equally strong with the parent as regards one or more characters, there will always be characters in which it is weaker, and therefore as a whole it will be less perfect. This is quite the case with willows. The most imperfect simple hybrids are those which S. viminalis and S. cinerea form with S. triandra; and if we compare their peculiarities, we find that they differ from each other more than all other willows which form hybrids in free nature. 8. arbuscula an alpine willow of low stature, with the leafy stem of the catkin is very different from 8. purpurea, a low-ground species. ‘Th, etificial hybrid between them is so imperfect, that it dies every * This view is distinctly stated in Darwin, Or., p. 288, ed. 3. WICHURA ON HYBRIDS. 77 year down to the ground, and never bears blossoms. SS. purpurea with confluent stamens, and S. viminalis with free stamens, form a hybrid with very irregular pollen. On the contrary, the pollen of S. (caprea+viminalis), both of the parents of which have free stamens, has much more regular pollen. The more different the parent species, the more imperfect the hybrids. Examples might, moreover, be adduced of more complicated hybrids in confirmation of this position. It follows that those species only can combine to form hybrids which agree in a proportionally large number of peculiarities and the relative biological conditions, which accords with the fact that only cognate species or nearly allied genera can combine. Were it necessary to prove by experiment that every species, in order to maintain itself in certain vital conditions, requires all the peculiarities with which it is endowed, one could think of nothing more appropriate than hybridizing, which calls into action in a weak and impaired intermediate condition all the constant differences of the parents. Were the hybrid as vivid and vigorous it would be a contradiction to this hypothesis. The constantly increasing sterility in hybrids, and their dying out when fertilized with their own pollen, belongs probably to another class of phenomena. It is notorious that families which have the seeds of disease in them, and yet intermarry, die out after some generations; and the raisers of varieties are well aware that all abnormal peculiarities in plants and animals increase, if attention is paid to them in successive generations, so that propa- gation is confined to these abnormal individuals. If a hybrid is fertilized for successive generations with its own pollen, indi- viduals come together which have the same weak point, viz. that of reproduction. The increase of weakness and sterility, and the rapid dying out of hybrids by continual impregnation with their own pollen, agrees perfectly with the above-mentioned circum- stances. This is exactly Darwin’s view of interbreeding causing sterility in successive generations. Aigilops spelteformis, Jordan (2 (2 44. ovata, L.+ 3 Triticum vulgare, L.)+ 3 TL. vulgare) is an apparent exception to this rule. Esprit Fabre raised in 1858, from a spontaneous hybrid (4fgilops ovata+ Triticum vulgare), Aigilops triticoides, Requien, and at a later period Godron bred an artificial hybrid from the same parents, and fertilized this again with the pollen of Triticwm vul- gare, which is now commonly multiplied in gardens, under the same of Agilops spelteformis, while the primary hybrid is very 78 ROYAL HORTICULTURAL SOCIETY. unfruitful. In this second hybrid it is to be observed that there are three parts of Triticwm vulgare, and in consequence it is nearly accommodated to the vital conditions of 72. vulgare. We must remember, however, that it is propagated only artificially, The hybrid has not yet been found wild, and is therefore rare, if it exists at all, and of no great power of endurance. So long as hybrids, like stars, were regarded as freaks of nature, they added nothing to our knowledge; but when it was ascer- tained that the same laws existed in the formation of monsters, though differently directed, they became a fertile source of infor- mation respecting morphology; and so hybrids, if looked upon as products of a normal fertilization under extraordinary circum- stances, may teach us important lessons respecting the generation of plants. When both parents belong to the same species, we cannot tell what part the male and female parent take respectively in the formation of their progeny. But dissimilar factors are united in hybrids, and an intermediate form is the consequence. The products which arise from reciprocal crossing in plants, un- like those which are formed amongst animals, are perfectly alike. It is of no consequence which is the male and which the female parent. It is therefore a mathematical necessity that the pollen- cells must have just the same part in the act of generation as the ovules. The following observations in the form of aphorisms are to be considered conjectural, and require to be submitted to proof :— 1. Setting out from the fact that every branch, with a few ex- ceptions, repeats perfectly the type of the plant from which it springs, and that the origin of every branch is referable to the development and division of a single cell, it must be allowed that the cells of plants partake of their specific peculiarities, so that, under fayourable circumstances, they can reproduce new indi- viduals. 2. Embryo-cells and pollen-tubes are cells. They must contain therefore the type of a certain form, which will appear pure and unmixed on the growth of the cells into new branches. 3. The secret of reproduction depends on the combination of two different cells into a common whole. Accepting this as an axiom, it is natural and necessary in the union of two cells if they belong to differently constituted individuals, that a more or less perfect intermediate form should arise, whose form is not altered, whether a or b supply the pollen; for each of the two. cells, whether embryo-cell or pollen-tube, bears in itself the type of the WICHURA ON HYBRIDS. 79 individual from which it was taken, and each of the two species gives to the new structure a numerically equal part, namely one cell. Both united in opposite crossing must give the same inter- mediate form, in which both species have entered in equal pro- portions. 4, Embryo-cells and pollen-tubes give exclusively the subse- quent peculiarities to the product in consequence of their con- taining within them the type. The relation of the mother plant to the embryo after the completion of impregnation is that of the stock to the graft. Both nourish a strange individual, and are intimately connected with it, without exercising any influence whatever on its typical peculiarities. 5. If the remaining cells, on their growth into branches, repro- duce as a rule the same individual of which they are the essential part, experience teaches, on the contrary, that in the process of production many individuals of abnormal structure—that is, varieties—make their appearance. 6. Since the sexual union of differently constituted individuals (that is, hybridizing) always produces a being intermediate between the type contained in the ovule and that in the pollen-tube, we may regard it as a law which has equal weight in the origination of varieties. 7. The existence of a variety is therefore a proof that the ovule or pollen-tube from whence it sprung, or both, must have had a type departing from that of the normal species. 8. The embryo-cells and pollen-tubes have therefore not merely the function of reproducing the individual, but also of new ab- normal forms. 9. In hybrids the power of forming varieties exists especially in the pollen, in a less degree in the ovules; and this is probably also the case in pure species. 10. If we reflect that the new individual arising from impreg- nation is intermediate between the type of the pollen of the male and the embryo-cell of the female, we must, in order to explain the form of the variety, assign to the variety-producing sexual cells a tolerably wide departure from the ancestral type. 11. If a variety-forming ovule combines with a variety from pollen-grain, so abnormal a form may arise from the union that we may perhaps explain in this way the origin of Gertner’s ex- ceptional types, assuming the correctness of his observation. 12. It is doubtful whether the variety-forming power of the pollen can be seen from outward inspection; this certainly is not 80 ROYAL HORTICULTURAL SOCIETY. possible in all cases. There are very variable plants with regular pollen, as Salix nigricans, S. Lapponum, and the bistigmatic Carices. On the contrary, we have plants with irregular pollen, like hybrids, which are distinguished by the greater or less stability of their productions, as Salix fragilis, Trifolium mon- tanun, Barbarea vulgaris, but not B. stricta, Potentilla ineana, Hierochloé,and many others. But in the greater number of cases, as, for example, amongst hybrids, in many cultivated plants, in many indigenous plants conspicuous for white or light-coloured blos- soms, and finally in a great part of the very variable wild plants, as hawkweeds, roses, the shrubby brambles (but not Rubus cesius and zd@us, which yield no varieties and have regular pollen), mul- tiformity in the pollen and great variability are combined. It is also possible that in the multiformity of the pollen of these plants, we see the variability of their offspring pointed out as it were in embryo, or in other words, the increasing variability of the progeny of hybrid pollen must be referred to an irregular di- vision of the mother pollen-cell as its proximate cause. Mr. Darwin believes that there is some connexion between sterility and variability ; and there is suggestive matter in these observa- tions in other directions. Finally, a parallel may be drawn between hybrids and many cultivated plants. A common point in both consists in the fact that they are not fully accommodated to the conditions under which they live. Hybrids are not so because, in consequence of their abnormal generation, they have inherited only a portion of the peculiarities which belong to their accommodation, and culti- vated plants because, from artificial treatment, they are kept in climatic and local conditions for which they were not destined*. The history of all our cultivated plants, so far as it is known, shows this. ‘Transported from free nature into the garden, from a warm into a cold climate, the plant at first preserved its pecu- liarities for a time; then slight changes crept in; more followed, till at last, by repeated generation, scarcely one of the individuals from seed is like the other. In this state the pollen of many * It should be observed that in a state of nature plants are very frequently found under conditions which are not the most suited to their nature, but in places where they are able to maintain the struggle of life against others by which they would be overwhelmed. ‘This is a fact which is too little attended to by cultivators. Some excellent observations on this subject by the Dean of Manchester will be found in the first volume of the former series of this Journal, p. 44.—Eb. WICHURA ON HYBRIDS. 81 plants is quite like that of hybrids, and all the forms are found in it which have before been adduced as phenomena in the pollen of hybrid willows. Most cultivated varieties of Primula auricula, Hyacinthus orientalis, Tulipa Gesneriana, Solanum tuberosum, Brassica oleracea, Mathiola ineana, Antirrhinwm majus, Cineraria cruenta, and Verbenas have very strikingly irregular pollen: In a white variety of Oineraria cruenta a tetrahedric confluence of the pollen-grains was found like that in 8. (cimerea+ = t - PRINTED BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. PIRST-CLASS ILLUSTRATED GARDENING PUBLICATION. Published Weekly, price Threepence, Petes Fourpence. JOURNAL OF “HORTICULTURE COTTAGE GARDENER, COUNTRY ec urcee EDITED BY GEORGE W. JOHNSON, F.R.ELS., AND ROBERT HOGG, LL.D., F.LS. Assisted by a Staff of the best Writers on Practical Gardening, and numerous Amateur and Professional Correspondents, eminent in the various depart- ments of Horticulture and other rural pursuits connected with the household. This long-established and widely-cireulating Journal consists of thirty-two pages of | letterpress, with occasional supplements of eight additional pages ; and is richly Illustrated with Wood Engravings in the highest style of the art. The subjects treated on embrace every department of gardening, and rural and domestic economy. 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Natural History and Botany, so far as they relate to gardening and husbandry, are amply treated on, and embrace Zoology, Geology, Mineralogy, Meteorology, and oe logical, Structural, Systematic, and Popular Botany. ‘Biographies and Portraits of the most celebrated horticulturists. Reviews of new books relating to the above subjects ; reports of horticultural and powltey societies’ meetings throughout the bountry’; ; and penomtste notices. To Advertisers, the Journal of Horticulture ‘will be found a valuable and effective medium, from its extensive circulaticn among the middle and higher classes, A SPECIMEN NUMBER FREE BY POST FOR FOUR SPiwaatin JOURNAL OF HORTICULTURE & COTTAGE GARDENER 1 OFFIC, 171 FLEET STREET, LONDON, E.C.; And to be had of all Booksellers and at the pag Stalls. se ma ee ee WICHURA ON HYBRIDS. 81 plants is quite like that of hybrids, and all the forms are found in it which have before been adduced as phenomena in the pollen of hybrid willows. Most cultivated varieties of Primula auricula, Hyacinthus orientalis, Tulipa Gesneriana, Solanum tuberosum, Brassica oleracea, Mathiola incana, Antirrhinum majus, Cineraria eruenta, and Verbenas have very strikingly irregular pollen. In a white variety of Cineraria cruenta a tetrahedric confluence of the pollen-grains was found like that in S. (cimerea+incana). Keelreuter therefore says rightly, “The nature of plants and beasts is in a certain degree like that of hybrids, as soon as in any way they are removed from that destination for which they are especially fitted.” Where culture and hybridizing concur, the consequences of disaccommodation are naturally quicker and more extensive than where only one of these is at work. Thus we find in the Fancy Pelargoniums, the Giant Pansies, the Calceo- larias, and the Fuchsias, variability and multiformity of pollen in the highest degree. All these plants have irregular pollen, and in many individuals to a surprising extent. It is probable, though it has not yet been proved, that, as in hybrids, irregularity of pollen in cultivated plants favours variability. If gardeners, in the raising new varieties, would have recourse to the microscope, and let those individuals remain for seed which have the most irregular pollen, or if they would use the most irregular pollen in artificial impregnation, they would in all probability materially expedite the accomplishment of their wishes. At all events this remarkable position arises from our discus- sion, that imperfect accommodation gives to an organism an in- creased tendency to form varieties. Does, then, the same law prevail in nature? Plants are subject to the most different local and climatic conditions. Organisms which at any former time were adapted to climate and locality, must, when change of con- dition takes place, gradually cease to be accommodated. Had they in this state of transition possessed only the degree of variability which the greater number of wild plants now exhibit, their persistence would have been placed in question. If varia- bility, however, increased with increasing disaccommodation, there might well be one among the many varieties which, suited to the new condition, would have full scope, while the other less adapted forms would be displaced, whether change in combination with “natural selection”? be the agent, or whether matter endowed with life, in consequence of an inherent necessity, accommodates itself to a law of conformity suited to outward circumstances. VOL, I. G 82 ROYAL HORTICULTURAL SOCIETY. Teleologically considered, there is, in the variability of unaccom- modated species arising from generation, a struggle to produce a new form suited to the altered conditions; and hence it follows that the dying out of species and the origination of new forms are links of the same conditions, just as when an individual dies to perfect and mature the seeds from which it arises with new life in a numerous offspring. XV. Note on Adiantum Farleyense. By Tuomas Moort, F.LS., Chelsea Botanic Garden. Iw the Report of the exhibition held at South Kensington, on the 29th of July last, will be found a brief notice of this fine novelty, in the following terms :—“ A magnificent vigorous-growing fern, with the fronds of the size and form of those of A. trapeziforme, but pendent, and the large pinnules deeply crenato-lobate. One of the most beautiful of the Adiantums.”” A subsequent examina- tion of specimens of the plant, shows that these hasty memoranda are by no means too laudatory. Viewed in the mags, as seen on the occasion of the show in question, the affinity of this Adiantwm appeared to be with A. tra- peziforme as mentioned above; but the fertile fronds, which are, it seems, but sparingly produced, bear a much closer resemblance to A. tenerum. It appears, however, to be distinct from both, and may be characterized and described as follows :— A. FARLEYENSE: fronds supra-decompound; pinnules chartaceo- membranaceous, slightly glaucous beneath, rhomboid; the terminal ones cuneate at the base, those of the sterile fronds large (1-13 inch), dilatato-rhomboid; the posterior margins recurvo-falcate, the anterior deeply lobate ; the lobes dichotomously inciso-laciniate, with blunt entire (without serratures) segments, those of the fertile fronds smaller, rhomboid-oblong, slightly lobed; sori approximate, terminal on the lobes, oblong ; indusium entire ; stipes and rachides glossy ebeneous. Stipes 12-15 inches long, black, shining, terete, with a shallow groove in front. Fronds of pendent habit, everywhere smooth, quadripinnate or decompound, of a bright light-green colour, somewhat glaucous beneath ; the sterile more abundant than the fertile, densely leafy, their lamina about 20 inches long by 24 inches broad; the fertile with the pinnules smaller and less crowded. Pinnules chartaceo- membranaceous, petiolate, the terminal ones more or less cuneate at the base, articulated ; the fertile about ? inch long, rhomboid-oblong, divided into shallow lobes along the anterior soriferous margins; the MR. T. MOORE ON ADIANTUM FARLEYENSE, 838 sterile larger and more crowded, 1-1 inch long, dilatato-rhomboid, the posterior margins recurvo-falcate, the anterior deeply lobate, the lobes inciso-laciniate in a dichotomous manner with the ultimate divisions linear, obtuse, and quite free from serratures. Sori numerous, crowded, oblong, variable in size, terminal on the shallow lobes; indusium oblong, entire. Rachides and petioles everywhere glossy ebeneous. Hab. Barbados. It will be seen that, although evidently related to A. tenerum, this beautiful novelty differs from it in the larger size of its pinnules, and in the regularly dichotomo-laciniate condition of the margin of the sterile pinnules, which are also entirely free from the small serratures which occur so distinctly on the sterile portions of the fronds of A. tenerwm. To these differences may be added the dimorphous development of the plant, so entirely different are the elegantly-fringed sterile pinnules from the more contracted fertile ones. Asa garden plant it is far more beautiful than either of the species with which it has been compared. It is, in fact, one of the most charmingly graceful species yet known ot perhaps the most lovely genus of the pre-eminently lovely family of ferns. Adiantum Farleyense was, ay am informed, introduced to this country by T. D. Hill, Esq., of London, by whom it was received from his friend T. G. Briggs, Esq., of Barbados, West Indies. Mr. Briggs’s residence in that island being called Farley Hill, the fern has been christened as a memento. The magnificent specimen ex- hibited at South Kensington was presented by him to Col. Miles of Burton Hall, Malmesbury, to-whose gardener, Mr. J. Green, I am indebted for the material whence the foregoig description has been derived. Mr. Green states that the sterile fronds are very numerous in comparison with the fertile ones, and that they are always deeply cut; moreover, that the young fronds are of a beautiful pink colour, which they retaim until they acquire their full size. This variation in colour adds very greatly to the beauty of the plant. P.S.—Since the above has been in type, I have learned that this fern is a seedling raised at Farley Hill, by which I infer that it is of garden origin, and not fere nature. It is probably therefore a well-marked sport of A. tenerwm, or it may possibly be a hybrid between. A. tenerwm and Lo Commencement of a New Volume. FIRST-CLASS ILLUSTRATED GARDENING PUBLICATION. Published Weekly, price Threepence, Stamped Fourpence, JOURNAL OF “HORTICULTURE, COTTAGE GARDENER, “AND COUNTRY CENTLEMAN. EDITED BY. GEORGE W. JOHNSON, F.R.HS., AND ROBERT HOGG, LL.D., F.LS. Assisted by a Staff of the best Writers on Practical Gardening, and numerous Amateur and Professional Correspondents, eminent in the various depart- ments of Horticulture and other rural pursuits connected with the household. This long sobatlINel and widely circulating Journal consists of thirty-two pages of - letterpress, with occasional supplements of eight additional pages ; and is richly Illustrated -with Wood Engrayings in the highest style of the art. The subjects treated on embrace every department of gardening, and rural and domestic 4 economy. The Horticultural department treats of all outdoor and indoor operations of the fruit-, flower-, and kitchen-garden ; embracing the management of the stove, greenhouse, con- servatory, vinery, pine-stoye, and orchard-house; and the cultivation of melons, cucum- bers, and mushrooms; forcing both of fruit, flowers, and vegetables; notices of all the new fruits, flowers, and vegetables : arboriculture, and more particularly fruit-tree culture and ~ pomology ; landscape gardening and garden architecture; descriptions of all the newest inventions in garden structures, tools, and implements ; and a detail of work to be done in each department during every week in the year.. In Rural and Domestic Economy, it treats of the farm and poultry-yard ; allotment farming; the dairy; the pigeon-house, and rabbit-and bee-keeping ; the treatment of soils, manures, cropping, and rotation of erops. Brewing; wine-making ; vegetable cookery. 5 and the preserving of fruits and vegetables. 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Swiss Carvings, Flower-Boxes, ‘China. ‘Flower- Stands, Pots, Jardiniéres, &c. _ Conservatory Architects, Horticultural Builders, and Hot-water Apparatus sprain geoh Branch Orchid-Pots. ee Horticultural Builders. Mosaic Tiles. . nae 5. * Seedsmen. Bronzed Figures, Vases, Hounteia seen in Ac- tion—all for Decoration sg Parks. and Gardens. >is ases, Fountains, and Garden ~ R. T. LOWE—FRUITS AND VEGETABLES OF MADEIRA, ETC. 161 XXXII. Some account of the Fruits and Vegetables of Madeira, the Canaries, and Cape Verdes. By R. 'T. Lown, M.A. Iw England, as in the greater part of continental Europe, the line between agriculture and horticulture is broadly enough marked. ‘It is not so in the Atlantic islands above indicated—the geniality of climate and uniformity of soil superseding the various special contrivances requisite, at least in Northern Europe, for the cul- ture of most fruits and vegetables, and breaking down most of the distinctions between the garden and the farm. Thus, while in _ England the turnip, carrot, bean, potatoe, apple, pear, and cherry are almost the only proper vegetables or fruits that can be said to oscillate between the separate provinces of the horticultural and agricultural occupier of the soil, in Madeira may be named, in ad- dition to the latter five, the sweet potatoe (Batata edulis Thunb.), French-bean (Phaseolus vulgaris L.), lupine, onion, inhame (Colo- casia antiquorum Schott), several kinds of pumpkin, coffee, sugar- cane, peach, apricot, mulberry, plum, guava, Spanish-chestnut, and, above all, the vine itself as proper field or agricultural produc- tions of the country. In the Canaries it is much the same, though on a smaller scale, the prevalent high and sweeping winds pre- cluding much abundance or success in cultivating fruits or vege- tables; and in the Cape Verdes, the list must be extended on the one hand, if it lose somewhat on the other, in order to include the mandioce, the physic-nut (Jatropha Curcas L.), the cocoa-nut, two or three kinds of custard-apple, the anana, papaw and banana. Still a residuum in each of these three groups of islands may be fairly held to represent the proper fruit and vegetable inmates of our English gardens; and of this residuum a list which shall also not exclude any of the esculent or economically useful plants generally cultivated, without professing to include every casual strageler, will best convey a notion of the state of horticulture in the east Atlantic insular superequatorial region. Last of the Fruits, Vegetables, and other Economic Plants more generally. cultivated in the Madeiran, Canarian, and Cape Verde Islands. ANONACES, 1. Axona Cunrimoria L.—Custard-apple or Cherimoya. In Madeira common in gardens in and about Funchal and fruiting every year from October to January abundantly, but not bearing good fruit at a higher eleyation than 300 or 400 feet above the VOL, I. M 162 ROYAL HORTICULTURAL SOCIETY. sea. In the Canaries and Cape Verdes it is extremely rare. It is called in Madeira by the Portuguese “ Anona,’’ which in the Cape Verdes is the name of A. reticulata L. The fruit softens, but scarcely changes colour when ripe, only becoming a little paler green or brownish. In Madeira it does not ripen com- pletely on the tree, but is gathered when apparently full-grown’ or beginning to soften, and kept several days till it becomes uni- formly soft and ripe. It has a sweet creamy vinous taste, melting, rich, and juicy, and, when fine and not over ripe, is a delicious fruit. There are, however, almost as many sorts or varieties in quality as trees differing in goodness. The best are about the size of the fist, with few or scarcely any seeds. It seems questionable whether this is more than a more pubes- cent, larger, and broader-leaved garden form or variety of 4. squa- mosa L., due to cultivation or locality. In the Madeiran cultivated plant the leaves vary much, according to the age and vigour of the tree, in shape, size, and pubescence; whilst the smaller the fruit is, the drier and fuller it becomes of seeds, and the more regularly and extensively squamoso-tuberculate. Indeed, at an elevation of 500 or 600 feet and upwards above the sea, it may be said to pass completely into A. sgwamosa L. In the Cape Verdes it is not generally known or acknowledged as distinct from the very abundantly naturalized A. sguamosa L. In fact I met with the real 4. Cherimolia Mill. twice only in the Cape Verdes—viz. in the Maniche garden in 8S. Nicoléo and in another garden at Paul in St. Antao. The statement, therefore, in the ‘ Flora Nigritiana,’ p. 205, that A. Cherimolia Mill. is “a very abundant plant and quite natu- ralized in the Cape de Verde Islands,” and again, in Dr. J. A. Schmidt’s ‘ Flora of the Cape Verde Islands,’ p. 260, that it is “ widely spread over the Island of S. Antonio” (S. Antao) “though only as a bush, seldom flowering and rarely attaining 6-8 feet in height,’ belong properly only to A. sqguamosa L. 2. A. sguamosa L. Very common in the Cape Verdes, and perfectly naturalized, especially in St. Iago, forming thickets or jungles in the valleys of the interior, and called “ Pinha;’’ but not distinctly recognized in either the Canaries or Madeira. The fruit is similar to that of A. Oherimolia L., but prominently pony or tubercular all over, and very inferior in oak 3. A. ruricunaTs L. Only less common than A. sguamosa L. in the Cape Verdes, and called “ Anona.”’ In Madeira it is only represented by a single tree or two, and it does not occur at all R. T. LOWE—FRUITS AND VEGETABLES OF MADEIRA, ETC. 163 in the Canaries. The fruit is spherical and simply areolate, like A. Cherimolia L., not squamoso-tuberculate. It is preferred in the Cape Verdes to the “ Pinha.” 4. A. Muricata L.—Sour-sop. Not very common even in the Cape Verdes, where it is called “ Pinhio;’” and in Madeira stunted, starved, and never fruiting. The large obliquely cone- shaped softly muricate green fruit has a fine briskly sharp rather than acid taste, totally different from the creamy softness of the three preceding species ; and though with a peculiar resinous or _erude and slightly fishy flavour, it is a very fine refreshing fruit. CRUCIFERACER. 5. Brasstca onuracea L. The various sorts of cabbage, ex- cepting savoys, are very generally cultivated in each of the three groups of islands,—but brocoli and cauliflowers in Madeira alone, and there only occasionally. Brussels-sprouts have not yet found their way; but I cultivated successfully for some years the French or German Chou-rave in Madeira. . , 6. B. camprstris L. 6 (B. Rapa L.). Turnips are now com- monly grown in Madeira, and more rarely in the Canaries and Cape Verdes. In the latter, especially in the interior of St. Iago, I have seen them in gardens, of an enormous size and first-rate quality. 7. Rapwanus sativus L. Radishes are not uncommon in Ma- deira and the Canaries; but I have only once seen them in the Cape Verdes, in a garden at Porto Praia in St. Iago, where, how- ever, they were remarkably fine and flourishing. CiLustacEm (GUTTIFER® auct.). 8. Mammna Americana L.—Mammee Apple; Mamio, Port. Very rare and scarcely fruiting in Madeira. Not seen in the Canaries. General in the Cape Verdes and fruiting regularly, the fruit ripening in the summer. It is a fine evergreen tree, with large Magnolia-like stiff coriaceous shining leaves and globose fruit like a hard brown ball, said to be very good. MALvVACER. 9. Gossyprum PUNCTATUM Schum. et Th. This white- or pale- blush-pink-flowered cotton-plant is largely cultivated and indeed subnaturalized in the Cape Verdes, but it is not known in Ma- deira and the Canaries, where one or two yellow-flowered shrubby M 2 164 ROYAL HORTICULTURAL SOCIETY. sorts or species are occasionally seen in gardens, but do not seem to flourish much. The Ochro (Hibiscus esculentus Li.) is not grown as an esculent in any of the islands. BoMBACER. 10. Apansonta picirata L.—Calabaceira, Baobab or Monkey- bread. Not in Madeira. 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