These coloured hybrids were originated by M.
Having obtained a first hybrid generation, he allowed the hybrids to self-fertilize, and recorded the result in a large number of instances (a thousand or more) as to the number of individuals in the first, second, third and fourth generations in which the character selected for experiment made its appearance.
Of late years some remarkably fine hybrids have been raised between the various distinct groups of narcissi, and the prices asked for the bulbs in many cases are exceedingly high.
The aboriginal stock of the Uganda Protectorate is undoubtedly the pigmy-prognathous, which has gradually been absorbed, overlaid or exterminated by better developed specimens of the Negro sub-species, or by Negro-Caucasian hybrids from the north and north-east.
Hybrids are also common, the canary breeding freely with the siskin, goldfinch, citril, greenfinch and linnet.
The hybrids thus produced are almost invariably sterile.
Osaria, auxaria, a bundle of osier or willow twigs), the common term under which are included the various species, varieties and hybrids of the genus Salix, used in the manufacture of baskets.
The occurrence of hybrids in nature explains the difficulty experienced by botanists in deciding on what is a species, and the widely different limitations of the term adopted by different observers in the case of willows, roses, brambles, &c. The artificial process is practically the same in hybridization as in cross-fertilization, but usually requires more care.
Hybrids are sometimes less fertile than pure-bred species, and are occasionally quite sterile.
Some hybrids, however, are as fertile as pure-bred plants.
So markedly is this the case with hybrids that in a few generations all traces of a hybrid origin may disappear.
Numerous hybrids have been raised, varying in colour from creamy white to salmon, pink, yellow, red and orange.
Amoena, amoena spectabilis, magnifica, paronychioides major aurea and amabilis; Alyssum maritimum variegatum; some of the dwarf varieties of Antirrhinum majus; Arundo Donax variegata; Begonias; Calceolarias; Cannas; Centaurea ragusina; Clematises, of which the hybrids of the Jackmanni type are best; Dahlia variabilis, and the single-flowered forms of D.
Of late years not only have many fine hybrids been raised artificially between various species, but some remarkable bigeneric hybrids (between what are considered two distinct genera) have also been produced (indicated in the list below by *).
Egtfally great gaps, however, may exist between males and females, between climatic phases or summer and winter forms. The attempt to find a physiological criterion has similarly failed; many forms that have been universally accepted as true species produce fertile hybrids (see Hybridism).
From the variety Bohea, or from hybrids of descent from it, came the China teas of former days and the earlier plantings in India grown from imported China stock.
Its naturalization in western Europe is very ancient, but the race supposed to have been introduced by the Romans (Phasianus colchicus) has been much modified within the last century or two by the introduction of the ring-necked Chinese form (P. torquatus), which produces fertile hybrids with the old breed.
They have been ousted by the more gorgeous looking hybrids, which have been evolved during the past Too years.
Maule, thinking a hardier blood might be infused into the potato by crossing it with some of the native species, raised hybrids between it and the two common species of Solanum native in this country, S.
Since the cultivation of cinchona trees was commenced in Java, India, Ceylon and Jamaica, several other species, as well as varieties and hybrids cultivated in those countries, have been used.'
Thirty mares put to a Burchell zebra produced seventeen hybrids, and subsequently twenty pure-bred foals.
Unlike Lord Morton's quagga hybrids, all the zebra hybrids were richly, and sometimes very distinctly, striped, some of them having far more stripes than their zebra parent.
But as equally distinct markings occurred on two pure-bred Highland foals out of mares which had never seen a zebra, it was impossible to ascribe the stripes on the foals born after zebra hybrids to infection of their respective dams. Further, the subsequent foals afforded no evidence of infection, either in the mane, tail, hoofs or disposition.
Moreover, while the faint markings on the foals born after hybrids completely disappeared with the foals' coat, the stripes on the three pure-bred colts persisted.
Some British authors have referred to the latter of these well-marked species certain Ducks that from time to time occur, but they are doubtless hybrids, though the secret of their parentage may be unknown; and in this way a so-called Bimaculated Duck, Anas bimaculata, was for many years erroneously admitted as a good species to the British list, but of late this has been properly discarded.
In the first ten years of attempting to make better hybrids, Borlaug's group made more than six thousand crossings of wheat.