91 8 PHENOMENA OF SEXUAL REPRODUCTION. 



kinds of streaks and blotches instead of a mixing of the colours of the flowers. Thus 

 a hybrid which Sageret obtained from Cucumis Chafe (female) with C. Melo Cania- 

 lupus (which had a reticulated rind) had a yellow flesh, a reticulate marking of the 

 rind and moderately prominent ribs like the male parent, but white seeds and an 

 acid flavour like the female parent. Another hybrid from the same species had, on 

 the contrary, the sweet flavour and yellow flesh of the male, with the white seeds and 

 smooth rind of the female parent. To this category belongs also the hybrid of 

 Cytisus Laburnum and purpureus [known as Cytisus Adami\ some of the branches 

 of which partially or entirely resembled one and some of them the other parent-form. 

 I have found what seemed to be a hybrid Antirrhinum majus^ in which the inflor- 

 escence bore on one side of the axis only dark-red, on the other side only yellow 

 flowers, while between the two halves stood a single flower which was half red and 

 half yellow. 



8. In addition to its inherited properties, the hybrid usually possesses characters 

 of its own by which it is distinguished from both its parent-forms. One of these 

 new characters, which occurs especially with variety-hybrids, is the tendency to vary 

 more strongly than its parent-forms. Species-hybrids are usually weak in their 

 sexual properties ; those derived from nearly related parent-species are, on the other 

 hand, more vigorous in their growth than their parent-forms, while hybrids resulting 

 from the union of species less nearly related are generally feebler in their develop- 

 ment. The luxuriant growth of the hybrids from nearly allied species is displayed 

 in their more numerous and larger leaves, in their taller and stouter stems, more 

 copious root' system, and larger number of shoots (stolons, scions, &c.). Hybrids 

 have also a tendency to a longer duration of life ; those of annual or biennial parent- 

 forms often live a number of years, probably in consequence of their producing 

 a smaller number of seeds. Hybrids are also characterised by commencing to 

 flower earlier, and continuing to do so longer and more abundantly, than the parent- 

 forms ; sometimes they produce an extraordinary number of flowers, which are also 

 larger, more enduring, and of brighter colour and stronger odour. They have also 

 a tendency to become double, their staminal and carpellary leaves to increase in 

 number and develope into petals. Along with this luxuriant vegetative growth, the 

 sexual organs are usually weak, and this in every possible degree. ' The stamens,' 

 says Nageli, ' are, it is true, in some cases perfect externally, but partially or altogether 

 infertile, the pollen-grains not attaining their proper development; while in others 

 the stamens are altogether abortive and reduced to rudiments. The pistils (gynae- 

 ceum) of hybrids are in most cases not distinguishable externally from those of the 

 parent species, but their ovules have no power, or only to a slight degree, of 

 becoming fertilised; either no oospheres are formed, or the embryos which begin 

 to be developed from the oospheres perish sooner or later. Under favourable 

 circumstances, when fertile seeds are produced, their number is smaller, and they 

 manifest a certain degree of feebleness in their slow germination and the short 

 duration of this capacity.' The feebleness of the sexual function is in some 

 variety-hybrids scarcely perceptible, in others but small ; in general it is the more 

 marked the more distant the genetic and sexual affinity of the parent-forms. When 

 species-hybrids have the power of producing seeds by self-pollination, and this is 

 repeated in the progeny, their fertility generally diminishes from generation to 



