HYBRIDIZATION. 



63 



If the seeds of fruit-trees, such as Apples, 

 Pears, Peaches, Apricots, or Plums, &c, be 

 sown, and the young plants grown on to the 

 fruiting stage, it is but rarely that they are like 

 the parent tree that bore them. They may 

 perchance be better, but as a broad rule are 

 degenerate reversions from the seed parent. 

 This may be, and often is, due to the flowers of 

 the seed-parent having been fertilized by pollen 

 from unsuitable or inferior varieties of the same 

 tree. If it is wished to rear a seedling from the 

 Ribston Pippin Apple, or Doyenne du Cornice 

 Pear, or the Victoria Plum, and it is desired 

 that the seedling should resemble or be exactly 

 like its parents, it is only a logical conclusion 

 that pollen should be used from the same iden- 

 tical variety, and also precautions adopted 

 against the occurrence of accidental cross-fertili- 

 zation. 



Double Flowers. 



What are usually known as "double flowers" 

 are those in which one or both of the essential 

 whorls of the flower, that is to say, either the 

 stamens, or the pistils, or both, are transformed 

 into sepals or petals. It would be too much 

 to say that "double flowers" are more beautiful 

 than normal or " single " ones, but there is no 

 gainsaying the fact that they are often more 

 showy and more long-enduring than are the 

 types from which they sprang, and so they lend 

 themselves more conveniently to the practical 

 requirements of the florist and decorator. Al- 

 though "double flowers" are now and then met 

 with in a state of wild nature, they are mainly 

 due to the effects of cultivation. It is generally 

 acknowledged that these monstrosities are the 

 result indirectly of overfeeding. The over- 

 stimulation of the plant by a rich supply of 

 food, destroys the natural balance that normally 

 exists between vegetative growth and sexual 

 vigour. Thus the petals are increased in size 

 or in number, at the same time that the stamens 

 or pistils are aborted and become petaloid. It 

 seems a paradox to assert that overfeeding 

 causes sexual sterility in plants, but it is well 

 known to be a fact, and it is quite possible for 

 the hybridist to rear double-flowered varieties 

 and races of plants by turning this knowledge 

 to advantage. In the case of Balsams (Impatiens) 

 and Stocks (Matthioli), &c, the tendency to pro- 

 duce double flowers has not only been acquired 

 by culture, but has become hereditary, and the 

 same is true in the case of Roses, Hollyhocks, 

 and other garden flowers. The first step in the 

 rearing of double flowers, then, is overfeeding 

 the seed-parent, so as to cause the production of 



petals at the expense of stamens. At first only 

 an odd stamen or two may be petaloid, and 

 these only in one or two flowers; but this once 

 observed, the battle may easily be won by care- 

 fully following up the advantage so gained. In 

 plants that are constantly overfed such petaloid 



Fig. 80. —Petaloid Stamens of Camellia. 



stamens may often be seen, as in Tulips, Azaleas, 

 Single Camellias, and other flowers, especially 

 so in those flowers having numerous stamens, 

 as in Roses, Pseonies, Carnations, Malvas, 

 Poppies, or Anemones. When petaloid stamens 

 (fig. 80) are detected, the point is to use the 

 pollen from these only, — on the stigma of the 

 same flower, — or preferably of another flower 

 having more than its normal number of petals on 

 the same plant. This is the plan adopted by the 

 Italian Camellia raisers, and also by the raisers 

 of Double Azaleas in Belgium and elsewhere. 



In some double flowers, such as Pinks and 

 Carnations, Narcissi and Roses, it often happens 

 that the duplication of petals is confined to the 

 stamens, the styles or stigmas being normal and 

 intact, and such flowers, if fertilized with pollen 

 from the petaloid stamens of other flowers, often, 

 indeed usually, produce seeds that yield double- 

 flowered varieties. 



If flowers become so perfectly double that all 

 the stamens and stigmas are aborted, it follows 

 that they cannot while in that state bear seeds, 



