CHAPTER VII.

POLLINATION

=Pollination.=--The act of conveying the pollen from the anther to the stigma.

=Close-pollination=--=Self-pollination=.--The transfer of pollen to a stigma of the same flower.

=Cross-pollination.=--The conveyance of pollen to the stigma of another flower.

=Crossing.=--The operation or practice of cross-pollinating.

=Fertilization=--=Fecundation=--=Impregnation=.--The action of the pollen upon the ovules.

=Close-fertilization=--=Self-fertilization=.--The action of pollen upon the ovules of the same flower.

=Cross-fertilization.=--The action of pollen upon the ovules of another flower of the same species.

=Individual-fertilization.=--Fertilization between flowers upon the same plant.

=Hybridizing.=--The operation or practice of crossing between species.

=Hybridism=--=Hybridity=.--The state, quality or condition of being a hybrid.

=Hybridization.=--The state or condition of being hybridized, or the process or act of hybridizing.

=Cross.=--An offspring of any two flowers which have been cross-fertilized.

=Individual-Cross.=--An offspring of two flowers on the same plant.

=Cross-breed=--=Half-breed=--=Mongrel=--=Variety-hybrid=.--A cross between varieties of the same species.

=Hybrid.=--An offspring of plants of different species.

=Half-hybrid.=--A product of a cross between a species and a variety of another species.

=Derivative or Derivation-hybrid=--=Secondary-hybrid=.--A hybrid between hybrids, or between a hybrid and one of its parents.

=Bigener=--=Bigeneric hybrid=.--A hybrid between species of different genera.

=Bigeneric half-breed.=--A product of a cross between varieties of species of different genera.

=Mule.=--A sterile (seedless) hybrid.

GENERAL REQUIREMENTS.--In order to understand the methods of pollination, the reader must be able to recognize the parts of the flower. The fuchsia, Fig. 90, shows the parts distinctly. The open flower, on the right, contains four well-marked series of organs. The first series is composed of four narrow and leaf-like parts or sepals, collectively called the calyx. Borne upon these is the corolla, made up of four blunt and variously colored petals. The next series comprises eight slender stamens or male organs (_S_). The thread-like portions or stalks of these are the filaments and upon them are borne the anthers. The anthers contain the pollen. The last and innermost series is a pistil or female organ (_P_). The pistil is made up of three parts: the ovary, which develops into the seed-pod, the style or slender portion, and the stigma, or enlargement at the end. The ovary in this case is the oblong body borne at the base of the flower and upon which the other parts stand. The style runs through the flower to the ovary.

The modifications of the flower are numberless, both in form and number of parts, but these four series of organs--the calyx, corolla, stamens and pistils--always comprise a complete flower and they are arranged in the order named. A perfect flower is one which contains both stamens and pistils without any reference to the surrounding or leaf-like organs. Many flowers are imperfect or contain only one sex. When the sexes are borne in different flowers upon the same plant, the species is said to be monœcious; and when they are borne upon different plants the species is diœcious. Sometimes the inflorescence is mixed, some flowers being perfect, some staminate and some pistillate, all upon the same plant; such species are polygamous. Most garden plants have perfect flowers. Many nut-bearing trees are monœcious, as walnuts, butternut, hickories, chestnuts, hazels and filbert and oaks. Some of the composite plants are also monœcious, the large head bearing staminate flowers in one part and pistillate in another. Pumpkins and squashes are monœcious and so are most varieties of melons. Fig. 91 shows a pistillate pumpkin flower with the ovary or young pumpkin below, and Fig. 92 a staminate flower which lacks the enlargement below. Among diœcious species may be mentioned the willows and poplars.

The ovary contains the ovules. When these are acted upon or fertilized by the pollen they develop into seeds. The pollen falls upon the stigma or upper extremity of the pistil, and each grain germinates and sends a tube down through the style to an ovule. The stigma is a slightly roughened soft surface, and when it is "ripe," or ready to receive the pollen, it becomes slightly moist or sticky. In most plants the stigma is merely a circular expansion of tissue (Fig. 97), but sometimes it is divided into lobes and the lobes remain closed until it is ready for the pollen. The fuchsia stigma is composed of four lobes, which are closed in Fig. 90. Fig. 93 shows the two-lobed stigma of the trumpet-creeper or tecoma before the flower is ready for pollination. Fig. 94 shows the stigma open, in condition to receive the pollen. In these flowers the stamens are hidden in the tube of the corolla.

The pollen is nearly always in the form of very small grains, which become dry when ripe. In some plants, notably in orchids, the pollen is borne in large masses known as pollinia. When the anther is "ripe" it assumes a yellow, orange or brownish cast and the pollen is discharged through a split in the side, a chink at the apex or other aperture. The pollen may fall upon and fertilize the stigma of the same flower, in which case the flower is said to be self-fertilized, or oftener it is carried to another flower by insects, winds or other agencies. Most plants possess some contrivance which renders self-fertilization difficult and cross-fertilization easy.

There are many degrees of cross-fertilization. The cross may take place between two flowers in the same cluster or between two clusters upon the same plant; or it may take place between distinct plants, either of the same or of another species. Fertilization between flowers on the same plant is known as individual-fertilization. The limits within which crossing is possible are not known, but the closer the species are related the more readily, as a rule, will they cross. One of the barriers which nature erects to prevent self or close-fertilization is a difference in time of maturing of the two sexes. In any flower the two parts are rarely ready at the same time. Flowers in which the stamens mature first are said to be proterandrous, and those in which the pistils mature first are proterogynous. In crossing such species, flowers of different ages can usually be found so that the parts can be brought together without difficulty. But when one series of organs in all the flowers of any species perish before the other series is mature, the pollen must be kept until the pistils are ready, or one sex must be forced or retarded artificially to accommodate the other. If the pollen matures first, it is only necessary to keep it a few days until the pistil is ready; but if the pistil matures first, and the plants cannot be handled artificially, the pollen must be kept over until the following season in order to effect any crosses.

The longevity of pollen is little understood. That of some species will keep much longer than others. It is supposed that, as a rule, it will not keep beyond a few days or weeks. If the pollen is to be kept, the anthers should be picked just before ready to burst and laid upon paper in a warm, dry and shady place until they dry up and the pollen is all discharged. The anthers must then be removed, and the pollen is securely wrapped in dry paper. If it is to be kept long it will probably be better to place it in small, closely cork-stoppered vials. It should be kept in a uniform temperature.

=Methods.=--All perfect flowers--those which contain both stamens and pistils--must be deprived of their anthers before the pollen is discharged, to prevent self-fertilization. This removal of the anthers is called _emasculation_. It is performed before the flower opens, and therefore before any foreign pollen could have reached the stigma. In some flowers, as in the tomato, Fig. 95, the stigma protrudes even before the petals are fully grown and emasculation must be performed very early. Even if the stigma is not mature, there is a chance that pollen will adhere to it and persist until conditions are fit for its growth.

The flower is generally emasculated by pulling out the anthers with pincers, but some large anthers can be hooked out easily by a very small crochet-hook or by a pin bent to a minute hook upon the point.

It is many times a tedious operation, however, to pull out the anthers without crushing them, and thus distribute some of the pollen. A surer and better plan with most flowers is to cut off the floral envelopes and the stamens near the base with a pair of small and sharp-pointed scissors which cut well at the point. _A_ in Fig. 90 shows the point at which this cut should be made in the fuchsia. With a little practice, one can cut off the parts quickly. Fig. 96 shows a tomato-flower after it has been emasculated in this fashion. Fig. 97 represents two flowers of _Nicotiana affinis_, one of which has been cut. One of the most important features of this method is the marking of the fruits which results in all species in which the calyx persists. The calyx, of course, does not develop and the crossed fruit can be distinguished at once, even though the label is lost. The tomato fruit in Fig. 98 lacks entirely the long leaf-like calyx lobes at the base. Fig. 99 shows upon the right a gooseberry fruit, of which the flower was cut, while that on the left illustrates an untreated fruit with the long persistent calyx. This marking of the calyx is useful in all the pomaceous fruits, like apples and pears, and even in capsular fruits, like phloxes and petunias, in which the calyx lobes remain green.

As soon as the flower is emasculated it must be securely tied up with a bag, to exclude pollen, as seen in Fig. 100. Netting of any kind is not safe in ordinary practice, for the pollen grains are small enough to pass through it. It often happens that the flower-stem is not strong enough to hold the bag, nor large enough to allow the bag to be puckered tightly about it. In such cases, all the remaining flowers in the cluster should be removed and the bag should be tied over a portion of the branch. The branch will often need to be cut off to accommodate the bag. If there are many large leaves about the flowers, part of them will need to be cut off. It is always a good practice to emasculate two or three flowers in the cluster--or all those of the same age--in order to multiply the chances of success. If flowers of different ages are emasculated, however, the bag will have to be removed several times to apply the pollen as the stigmas mature, and the chances of success will be lessened, for the flowers should be handled as little as possible.

Various bags have been devised and recommended for covering the flowers, but none of them yet introduced are equal to the ordinary grocers' manilla bags. The only difficulty is that the smallest size--the fourth-pound--is too large for many small subjects, but for these the bag can be cut off. A soft string, five or six inches long, is passed through one of the folds of the bag about an inch from the open end, as seen in Fig. 101, and is tied to hold it in place. To make the bag pucker tightly about the stem, it should be moistened just before it is used.

In some flowers which have long and thick tube-like corollas, and in which the stigma matures quickly, the end of the corolla itself may be tied up. The flowers of squashes and pumpkins are particularly adapted to this treatment, and one is shown in Fig. 102. The flower is tied before it opens. In squash-like plants the flowers usually open early in the morning and the flowers are tied up the preceding evening. The corollas soon wilt and bags must be used after the pollen is applied; and even if the corolla does not wilt and shrivel, insects sometimes eat through it and interfere with the experiment.

All imperfect flowers of course need no emasculation, but they must be tied up while yet in the bud to protect them from pollen.

As soon as the stigma matures--which will vary from one to six or seven days, according to the species--the pollen must be applied. The novice will be obliged to remove the bags occasionally, to see if the stigmas are ready. As soon as the shiny or glutinous appearance of the stigma is seen, pollination should be performed. The pollen is most easily secured by removing an anther when it is about to burst and breaking it open. If the anther is allowed to break open naturally, the pollen will be lost, or at least difficult to secure. There are various instruments recommended to aid in the transfer of the pollen. A camel's hair brush is often advised, but it is probably the poorest instrument which can be used. It wastes the pollen and also mixes it by holding it among the hairs, and it is often a difficult matter to apply pollen to the stigma evenly and in sufficient amount. The point of a small knife-blade is a better instrument. A still handier and better tool is made by flattening the point of a pin and then inserting the little scalpel in a handle, as shown in Fig. 103. With the point of this implement the pollen can be removed from the groove or opening in the side of the anther. It is commonly better, however, to place the unopened anther upon the thumb nail and crush it with the scalpel, when the pollen can be gathered up on the point and transferred to the stigma. In some species the pollen can be removed only by opening the anther-valves dexterously. Such is the case with the tomato; the point of the scalpel is inserted in a longitudinal groove or fold in the side of the anther, and as it is carried upwards the pollen is secured.

The stigma should receive an abundant supply of pollen. No harm can come from supplying too much while if too little is applied, some of the seeds will not mature or even the fruit may not set. It is well known that in many plants, at least, the pollen stimulates the development of the fruit-walls, as well as fertilizes the ovules, and a greater amount of pollen than is sufficient to produce the seeds themselves may therefore exert an important influence. Sometimes it is not necessary to use an instrument to transfer the pollen. If the pollen is copious and adheres to the anther after it is discharged, the anther may be simply rubbed over the stigma. An anther will ordinarily contain sufficient pollen to fertilize several stigmas. The whole surface of the stigma should be covered until it is colored with the pollen. Sometimes it will be found advisable to cut off the corolla from large flowers, if it was not done when the flower was emasculated, to facilitate the labor of applying pollen. The short stigmas of squashes, for instance, can be reached more easily if the corolla is removed, as in Fig. 104.

In order to prevent the mixing of pollen, the flowers from which it is to be derived should be covered while in the bud, the same as the flowers designed as the pistillate parents. Otherwise foreign pollen may be deposited upon the anthers by insects or winds.

As soon as the pollen is applied to the stigma, the flower should be tied up again the same as before. The bag should remain three or four days or a week, until the stigma has died and all danger of another pollination is removed. If the fruit is likely to be destroyed by birds or insects, it should be covered with netting bags as soon as the paper-bags are removed. These bags also serve to mark the crossed fruits, and to catch them if they should drop before the operator is aware. Of course all crosses should be labelled with the names of both parents and the date of the operation.

For ordinary operations, no especial outfit is necessary for the crossing of plants, but those who experiment largely will find that the work will be greatly facilitated by the use of a portable box in which the various requisites can be carried. If this box has a compartment for every article, the operator will see at a glance if anything is lacking before he goes to the field. Figs. 105 and 106 illustrate a convenient pollinating kit. This is made about 12 inches long, 9 inches wide and 3 inches deep. In the central portion is a compartment for bags and one for labels. At the right end, running crosswise, is a narrow compartment for string, and at its upper end is a small bottle of alcohol. Into this alcohol the scalpel and other tools are dipped whenever another kind of pollen is to be used, in order to destroy whatever pollen grains may adhere to them. In front is a compartment for a magnifying glass, and a long one to hold scalpel, brushes, crochet-hook and pencil. The note-book is held in the cover by a wire clasp.

It is rare that all the flowers which one pollinates will mature fruit. If one-half are successful on the average, the operator may be satisfied. External conditions have much to do with the success of the operation. Some species do not set well during very dry weather and some are impatient of confinement. But probably all plants which thrive under glass are more sure to give good results if pollinated under confinement, because conditions are under control.

=Crossing of Flowerless Plants.=--Ferns, lycopodiums, and their allies, pass through two stages of development, and fertilization takes place only in the first stage. When spores germinate, a small, thin, green tissue spreads over the soil. This tissue is the prothallus (or prothallium). Upon the prothallus, or somewhat sunken in it, the sexual organs appear. They are minute aggregations of cells. Some of these aggregations develop into sperm or male organs and some into germ or female organs. The sperm organ is known as an antheridium and the germ organ as an archegonium. Spermatozoids are formed in the antheridium, and these enter the archegonium and fertilize the germ cell. This fertilized germ cell then develops into the second stage of the species, or into that part which we know as the fern or the lycopod. During this second stage, the plant bears leaf-like organs and it also produces numerous spores. These spores will produce the prothallus again when sown. Ferns, therefore, are fertilized but once during their lifetime, and the spores are not the direct result of fertilization as are the seeds of flowering plants.

If ferns and other flowerless plants are to be crossed, therefore, the operation must be performed in the prothallic stage. It was long a matter of doubt among botanists as to whether crossing is possible among these plants, but it is now known that it does occur. It has been brought about repeatedly in cultivation. The sperm bodies are not transferred by hand, but the spores of the species between which crosses are desired are sown together and the transfer is allowed to take place naturally. The prothallia of ferns are nearly always diœcious (sexes borne on different plants), so that crossing in such cases is not improbable. Many spores should be sown to increase the chances of success, and care should be taken that the different kinds germinate simultaneously. Some species germinate quicker than others, and the operator must determine by previous trial what these differences are. (For methods of sowing spores, see page 24.) Only a small part of the plants will be likely to be crosses. In one of Lowe's experiments, only five plants out of 1,000 were undoubted crosses.

ORDINAL INDEX.

An Index to the natural orders or families mentioned in the Nursery List. A number in parentheses indicates the number of references to the family upon a page, if more than one occurs.

Acanthaceæ, 99, 115, 125 (2), 130, 133, 149, 158, 170, 183, 188, 198, 210, 216, 264, 273, 277 (2) Alangieæ, 106 Alismaceæ, 101, 107, 144, 217 Amarantaceæ, 108, 109, 156, 207 Amaryllideæ, 105, 108, 109, 138, 140, 142, 147, 148, 164, 169, 171, 173, 179, 185 (2), 190, 192, 199, 203, 206 (2), 207, 208, 215, 229, 231, 240, 247, 254, 280, 285 Ampelideæ (Vitaceæ), 110, 162, 195 Anacardiaceæ, 111, 166, 180, 222, 251, 262, 266, 271 Anonaceæ, 113, 122, 123 Apocynaceæ, 102, 104, 107, 108, 110, 115, 132, 152, 153, 178, 222, 231, 254, 275, 278, 282, 284 Araliaceæ, 120, 172, 192, 201, 238, 240, 267 Aristolochiaceæ, 121, 123 Aroideæ, Araceæ, 100, 107, 109, 110, 111, 114, 121, 123, 146, 199, 226, 238, 240, 248, 261, 262, 266 (2), 270, 272, 275, 281 Asclepiadeæ, 111, 123, 124, 140, 149, 157, 194, 199, 205, 223, 246, 249, 271, 272

Begoniaceæ, 132 Berberideæ, 106, 130, 134, 155, 182, 203, 209, 213, 215, 254 Bignoniaceæ, 102, 110 (2), 135, 154, 160, 180, 208, 276 Bixineæ, 128, 136, 206 Boragineæ, 111, 122, 138, 167, 172, 181 (2), 201, 218, 225, 228, 234 (2), 275 Bromeliaceæ, 99, 135, 141, 180, 250, 278 Bruniaceæ, 126, 134, 142 Burseraceæ, 110, 129, 139, 144

Cacteæ, 145, 183, 234, 245, 246, 248, 261 Calycanthaceæ, 149, 160 Campanulaceæ, 102, 151 (3), 156, 172 (2), 179, 209, 216, 218, 225, 249, 251, 259, 278 Canellaceæ, 151 Capparideæ, 152, 161, 254 Caprifoliaceæ, 97, 177, 216, 217, 219, 265, 275, 281 Caryophylleæ, 105, 121, 153, 157, 199, 220, 250, 255, 265, 269, 275 Casuarineæ, 154 Celastrineæ, 154, 155, 185, 228 Chenopodiaceæ, 132, 139, 235, 271 Cinchonaceæ, 107 Cistineæ, 163, 201 Combretaceæ, 162 (2), 259, 276 Commelinaceæ, 112, 166, 172, 177, 278 Compositæ, 99, 101 (2), 105 (2), 106, 108, 109, 112, 114 (2), 115, 120 (2), 121, 122 (4), 124 (2), 126 (2), 128 (3), 130, 132, 133 (3), 134, (2), 135 (2), 138 (2), 140 (2), 143, 147, 148 (2), 149, 152 (2), 153, 154, 155, 156, 160, 161 (2), 162 (3), 167, 168, 171, 173, 174, 177, 179, 180 (2), 181, 182, 183, 185, 186, 190, 191, 198, 199, 201 (3), 202, 205, 207, 210, 214, 215 (3), 216 (3), 220, 222, 228, 233, 238, 239, 241, 261, 263, 264, 265, 266, 267, 268, 269, 270, 272 (2), 275, 276, 281, 284, 285 Coniferæ, 97, 120, 126, 148, 155, 158, 170, 171 (2), 173, 188, 192, 210, 213, 249 (2), 250, 254, 257, 260, 267, 268, 276 (2), 277, 278 Convolvulaceæ, 121, 167, 207, 232, 274 Coriarieæ Cornaceæ, 126, 134, 167, 191, 232 Crassulaceæ, 142, 169 (2), 195, 211, 267, 268 Cruciferæ, 104, 109, 111, 120, 126, 130, 136, 138, 145, 146, 152, 169 (2), 176, 179, 184, 202, 204, 206, 211, 212, 220, 221, 223, 226, 241, 245, 259, 262, 267, 279, 281, 283 (2) Cucurbitaceæ, 97, 142, 171, 195, 220, 224 (2), 226, 257, 267, 271, 278, 283 Cunoniaceæ, 101 Cupuliferæ, 107, 135, 153, 160, 168, 186, 238, 258 Cycadaceæ, 157, 172, 178, 182, 285 Cyperaceæ, 152, 172, 240 Cyrilleæ, 173 Cytinaceæ

Datisceæ, 175 Diapensiaceæ, 190 Dilleniaceæ, 151, 177, 202 Dioscoreaceæ, 178, 276 Dipsaceæ, 266 Dipterocarpeæ Droseraceæ, 178, 180 (2)

Ebenaceæ, 178, 246 Elæagnaceæ, 181, 203, 268 Empetraceæ, 157, 167, 182 Epacrideæ, 101, 111, 125, 182, 224 Ericaceæ, 112, 120, 127, 132, 148, 154, 164, 169, 181, 182 (2), 183, 191, 211, 214 (2), 215, 219, 220, 225, 239, 257, 261, 283 Euphorbiaceæ, 98, 106, 145, 154, 162, 165, 185, 202, 203, 209, 222, 248, 254, 262, 272

Ficoideæ, 225 Filices, 175, 177, 187, 220, 238, 251, 255, 257 Frankeniaceæ, 189 Fumarieæ. See Papaveraceæ.

Gentianeæ, 161, 184, 186, 191, 214, 218, 225, 264, 275 Geraniaceæ, 127, 128, 129, 135, 184, 191, 207, 217, 226, 238, 244, 279 Gesneraceæ, 99, 103, 104, 128, 134, 177, 192, 193, 211, 212, 216, 229, 230, 259, 273 Gnetaceæ, 182 Goodenovieæ, 142, 174, 194, 215, 266 Gramineæ, 105, 112, 123 (2), 129, 141 (2), 146, 185, 199, 221, 247, 270, 274, 285 Guttiferæ, 149, 164, 190, 221

Hæmodoraceæ, 113, 200, 245, 265 Halorageæ, 199 Hamamelideæ, 143, 189, 200, 218 Hydrophyllaceæ, 230, 246 Hypericineæ, 123, 206

Ilicineæ, 206, 230 Irideæ, 113, 114, 121, 128, 137, 162, 170 (2), 172, 188, 189, 192, 202, 208 (2), 223, 230, 241, 262, 267, 269, 270, 277, 279, 283

Juglandeæ, 203, 209, 244, 257 Juncaceæ, 147, 210, 284

Labiatæ, 103, 106, 113 (2), 129, 131, 137, 146, 155 (2), 165, 166, 180, 183, 204, 206, 214, 215, 219, 224, 226, 231, 245 (2), 246, 248, 256, 263, 264, 265, 266, 267, 268, 270, 271, 276, 277 Laurineæ, 134, 151, 214, 246, 265 Leguminosæ, 98 (2), 102 (2), 103, 104, 105, 106, 109 (3), 110 (2), 111, 114, 115 (2), 120, 123, 125, 130 (4), 131, 132, 139 (2), 140, 141, 142 (2), 144, 146 (2), 147, 149, 150, 152 (2), 153, 154, 157 (3), 163, 164 (2), 166, 167, 170, 173, 174, 175, 176, 179 (2), 181, 184 (2), 186, 190 (2), 193 (2), 194 (2), 199, 200 (3), 201, 204, 207 (2), 211, 212, 213, 215 (2), 218, 219 (2), 220, 223, 225, 226, 229, 234, 238, 239 (2), 241 (2), 243, 246, 247, 251, 254 (2), 256, 257, 262 (2), 268, 270, 274, 276, 277, 280, 281, 283, 284 Lentibularieæ, 250 Liliaceæ, 104, 106, 107, 108, 112 (2), 114, 115, 122, 124 (4), 132, 133, 134, 137, 140, 141, 143 (2), 144, 148 (2), 150, 161 (2), 164, 165, 166, 174, 175, 176, 178, 179 (2), 183, 184, 185, 190 (3), 191, 192, 193, 202 (2), 205, 211, 212 (2), 213, 214 (2), 216, 218, 223, 225, 227, 229, 234, 238, 241, 248, 255, 257, 262, 264, 266, 267, 268, 269 (2), 274, 279 (4), 280, 281 (2), 284, 285 (2) Lineæ, 184, 217, 260 Loaseæ, 131, 137, 218 Loganiaceæ, 176, 191, 219 Loranthaceæ, 282 Lycopodiaceæ, 268 Lythrarieæ, 171, 212, 214, 220, 231, 255

Magnoliaceæ, 180, 206, 210, 218, 221, 225, 266 Malpighiaceæ, 101, 129, 143, 145, 221, 272 Malvaceæ, 98, 108, 138, 148, 168, 183, 189, 203 (2), 211, 212, 213, 221 (3), 226, 233, 239, 241, 271 Melastomaceæ, 100, 122, 134, 137, 141, 150, 156, 157, 172, 202, 213, 224 (2), 252, 270 Meliaceæ, 105, 106, 152, 155, 224, 265, 278 Menispermaceæ, 98, 162, 165, 224 Monimiaceæ, 126 Moringeæ, 226 Myoporineæ, 228 Myricaceæ, 166, 228 Myristiceæ, 229 Myrsineæ, 120, 163, 209 Myrtaceæ, 100, 113, 124, 128 (3), 131, 132, 148, 149, 150 (2), 152, 153, 174, 185, 199 (2), 224, 225, 229 (2)

Naiadaceæ, 115, 238 Nepenthaceæ, 230 Nolanaceæ, 108 Nyctagineæ, 97, 139, 226 Nymphæaceæ, 145, 230, 232, 282

Ochnaceæ, 194, 232 Olacineæ, 233 Oleaceæ, 161, 189 (3), 209, 216, 232 (2), 233 (2), 238, 248, 275 Onagrarieæ, 162, 163, 182, 190, 191, 210, 219, 233, 278 Orchideæ, 98, 99, 102, 103, 104, 113 (2), 114, 115, 130, 131, 137, 140, 141, 143, 144, 146, 149, 150, 155, 166, 173, 175, 178, 182, 212, 220, 223 (2), 225, 232, 234, 236, 247 (2), 265, 271, 277, 278, 280, 281, 285

Palmæ, 99 (2), 101, 121, 125, 128, 138, 140, 146, 154, 158, 165, 174, 178, 181, 186, 191, 207, 209, 211, 216, 218, 222, 223, 233, 234, 240, 248, 249, 251, 256, 257, 259, 264, 277, 278, 281, 283 Pandaneæ, 190, 240 Papaveraceæ, 103, 121, 137, 168, 176, 182, 184, 190, 223, 240, 262, 265 Passifloreæ, 152, 195, 241 Pedalineæ, 223, 268 Phytolaccaceæ, 249, 262 Piperaceæ, 245, 251 Pittosporeæ, 135, 144, 251 Plantagineæ, 98, 251 Platanaceæ, 251 Plumbagineæ, 121, 254, 272 Polemoniaceæ, 151, 164, 192, 219, 248, 254 Polygaleæ, 166, 212, 255 Polygonaceæ, 143, 148, 165, 183, 227, 255, 261, 270 Pontederiaceæ, 181, 255 Portulacaceæ, 106, 110, 146, 216 Primulaceæ, 111, 112, 127, 168, 172, 179, 204, 220, 256, 270 Proteaceæ, 102, 104, 127, 129, 198, 200, 211, 213, 215, 219, 246, 256

Ranunculaceæ, 100, 101, 103, 112 (2), 120, 126, 149, 162, 163, 167, 175, 183, 202 (2), 208, 212, 231, 239, 259, 276, 279, 284 Resedaceæ, 260 Rhamneæ, 134, 155, 166, 205, 210, 240, 248, 260 Rosaceæ, 98, 102, 105, 106, 107, 109, 116, 119, 136, 144, 158 (2), 161, 168, 169, 176, 185, 186, 192 (2), 210, 211, 217, 224, 232, 242, 243, 248, 252, 255, 256 (2), 257, 258, 259 (2), 261, 263 (2), 271, 272, 283 Rubiaceæ, 103, 114, 124, 139 (2), 144, 149, 151, 155, 156 (2), 160, 162, 165 (2), 167, 170, 191, 200 (2), 203, 204, 208, 219, 222, 230, 231, 240, 245, 250, 263 Rutaceæ, 100 (2), 101, 102, 103, 105, 107, 125, 131, 134, 135, 139, 149, 154, 161, 163 (2), 168, 170, 177, 178, 184, 193, 214, 217, 235, 247 (2), 255, 257, 264, 269, 285

Salicineæ, 255, 264 Sapindaceæ, 99, 104, 212, 224 (2), 230, 231, 271, 284 Sapotaceæ, 121, 131, 162, 208, 265 Sarraceniaceæ, 174, 265 Saxifrageæ, 102, 114, 125, 131, 141, 147, 148, 157, 162, 171, 175, 176, 184, 189, 194, 202, 206, 208, 241, 247, 262, 266, 267, 277 Scitamineæ (Zingiberaceæ), 108, 129, 147, 151, 168, 171, 201 (2), 222 (2), 227, 273, 285 Scrophularineæ, 108, 111, 112, 115, 122, 138, 142 (2), 147, 156, 157, 158, 177, 183, 192, 198, 208, 217, 223, 225, 241, 245, 261, 264, 265, 278, 281 (2) Selagineæ, 193 Simarubeæ, 142, 258 Solanaceæ 114, 126, 157, 173, 175, 181, 186, 208, 213, 220, 222, 231 (3), 245, 246, 249 (2), 255, 266, 269 (2), 278 Sterculiaceæ, 97, 124, 125, 140, 211, 213, 221, 229, 245, 264, 272, 277 Stylidieæ, 273 Styraceæ, 200, 274, 275

Taccaceæ, 275 Tamariscineæ, 276 Ternstrœmiaceæ, 101, 138, 150, 153, 185, 195, 273, 276 Thymelæaceæ, 174, 178, 181, 212 (2), 247, 249, 273 Tiliaceæ, 99, 114, 115, 121, 142, 181, 182, 198, 270, 277 Turneraceæ, 279 Typhaceæ, 280

Umbelliferæ, 100, 101, 112, 113, 122, 125, 126, 144, 156, 160, 167, 170, 177, 184, 186, 202, 219, 229, 241 (2), 269 Urticaceæ, 123, 138, 141 (2), 151, 155, 156, 179, 188 (2), 205, 213, 220, 226, 249, 251, 280

Vacciniaceæ, 104, 280 Valerianeæ, 156, 280 Verbenaceæ, 103, 108, 139, 147, 153, 161, 164, 213, 217, 256, 281, 282 Violarieæ, 108, 111, 168, 184, 207, 282 Vitaceæ. See Ampelideæ Vochysiaceæ, 282

Zanthoxyleæ, 105 Zingiberaceæ. See Scitamineæ Zygophylleæ, 198, 285

GENERAL INDEX.

Page.

Annular budding, 75

Bark-grafting, 88 Bass, 72 Bell glass, 39 Bigeneric half-breed, 286 Bigener, definition of, 286 Bigeneric hybrid, definition of, 286 Budding, 67 Budding, kinds of, 66 Bulbel, definition of, 26 Bulblet, definition of, 29 Bulb-scales, 28 Bulbs, definition of, 25

Callus, 49 Cions, cutting, 77 Cion, definition of, 63 Cleft-grafting, 81 Cloche, 39 Close-fertilization, definition of, 286 Close-pollination, definition of, 286 Corm, definition of, 29 Cormel, definition of, 30 Cross-breed, definition of, 286 Cross, definition of, 286 Cross-fertilization, definition of, 286 Crossing, definition of, 286 Cross-pollination, definition of, 286 Crown, definition of, 31 Crown-grafting, 76 Cuttage, definition of, 39 Cutting, definition of, 39 Cutting-grafting, 91

Damping-off, 22, 27 Derivative-hybrid, definition of, 286 Division, 51 Double-grafting, 91 Dressing of stocks, 69

Emasculation, 291

Fecundation, definition of, 286 Fertilization, definition of, 286 Flowerless plants, crossing of, 297 Flowers, diœcious, 288 -- monœcious, 288 -- perfect, 287 -- proterandrous, 290 -- proterogynous, 290 Flute-budding, 75 Free stock, 63 Fruit-grafting, 90

Graftage, definition of, 63 Grafting, 76 Grafting, definition of, 63 Grafting, kinds of, 66 Grafting-waxes, 92 Green-wood cuttings, 56

Half-breed, definition of, 286 Half-hybrid, definition of, 286 Hard-wood cuttings, 54 Heel cuttings, 48 Herbaceous-grafting, 89 Hybrid, definition of, 286 Hybridism, definition of, 286 Hybridity, definition of, 286 Hybridization, definition of, 286 Hybridizing, definition of, 286

Impregnation, definition of, 286 Inarching, 92 Individual-cross, definition of, 286 Individual-fertilization, definition of, 286

June budding, 73

Knaurs, 56 Knives, budding, 69 Knives, grafting, 84

Layer, definition of, 32 Layerage, definition of, 32 Layering, Chinese, 36 -- circumposition, 36 -- mound, 35 -- stool, 35 -- pot, 36 -- serpentine, 34 Leaf cuttings, 60

Mallet cuttings, 48 Mallet, for grafting, 87 Mongrel, definition of, 286 Mule, definition of, 286

Offset, definition of, 30

Plastic, for grafting, 92 Pollination, definition of, 286 Propagating frame, 39 Prothallus, 297

Raffia, 72 Regermination, 22 Ring-budding, 75 Root-cuttings, 53 Root-grafting, 76, 77 Root-tip, 33

Saddle-grafting, 79 Scales of bulbs, 28 Scions, cutting, 77 Scion, definition of, 63 Screens, for seeds and cuttings, 12 Seedage, definition of, 9 Seed-grafting, 90 Seeds, boring, 18 -- depth for sowing, 20 -- freezing, 17 -- Influence of light upon, 21 -- soaking, 17 -- sowing, 19 -- Transportation of, 23 Self-fertilization, definition of, 286 Self-pollination, definition of, 286 Separation, definition of, 25 Shield-budding, 68 Side-grafting, 80 Splice-grafting, 80 Spores, sowing, 24 Stem cuttings, 54 Stem-grafting, 76 Stick, of buds, 69 Stock, definition of, 63 Stolon, definition of, 32 Stratification, 15 String for tying, 71

Tongue-grafting, 76 Top-grafting, 76, 84 Tuber cuttings, 52 Tuber, definition of, 30 Tubular bedding, 76 Tying buds, 71

Variety-hybrid, definition of, 286 Veneer-budding, 75 Veneer-grafting, 80

Wax for grafting, 92 Whip-grafting, 76 Whistle-budding, 76

* * * * *

Transcriber Note

Where two different spellings of plant names appear, either the most used or the contemporary spelling was employed. All paragraphs split by images were rejoined and the images moved above or below the paragraph.

Definitions Missing

The Ordinal Index lists "Coriarieæ" without a page reference and it does NOT occur in the book's text.

Below is a list of referenced entries in the Ordinal Index for which the targets are missing from the text:

Castilleja Odontospermum Patrinia Tsuga