CROSS FERTILIZATION. 325 



When a grain of pollen comes in contact with the stigma, 

 it bursts and discharges its contents among the lax tissue 

 upon which it has fallen. The moving particles descend 

 through the tissue of the style, until one, or sometimes more, 

 of them finds its way, by routes. specially destined by nature 

 for this service, into a little opening in the integuments of 

 the ovulum or young seed. Once deposited there, the par- 

 ticle swells, increases graduallyin size, separates into radicle 

 and cotyledons, and finally becomes the embryo, — that part 

 which is to give birth, when the seed is sown, to a new in- 

 dividual . 



Such being the mode in which the pollen influences the 

 stigma, and subsequently the seed, a practical consequence 

 of great importance necessarily follows, viz. that in all cases 

 of cross fertilization the new variety will take chiefly after 

 its polliniferous or male parent ; and that at the same time it 

 will acquire some of the constitutional peculiarities of its mo- 

 ther.* Thus, the male parent of the Downton Strawberry 

 was the Old Black, the female a kind of Scarlet ; in Coe's 

 Golden Drop Plum, the father was the Yellow Magnum 

 Bonum, the mother the Green Gage ; and in the Elton 

 Cherry the White Heart was the male parent, and the Graf- 

 fion the female. 



The limits within which experiments of this kind must be 

 confined are, however, narrow. It seems that cross fertili- 

 zation will not take place at all, or very rarely, between dif- 

 ferent species, unless these species are nearly related to 

 each other : and that the offspring of the two distinct spe- 

 cies is itself sterile, or if it possesses the power of multiply- 

 ing itself by seed, its progeny returns back to the state of 

 one or other of its parents. Hence it seldom or never haa 

 happened that domesticated fruits have had such an origin. 

 We have no varieties raised between the Apple and the Pear, 

 or the Quince and the latter, or the Plum and Cherry, or the 

 Gooseberry and the Currant. On the other hand, new va- 

 rieties obtained by the intermixture of two pre-existing va- 

 rieties are not less prolific, but, on the contrary, often more 

 so than either of their parents ; witness the numerous sorts / 

 of Flemish Pears which have been raised by cross fertiliza- ^ 

 tion from bad bearers, within the last twenty years, and 

 which are the most prolific fruit trees with which gardeners 



* In early crosses between distinct species this Is particularly manifest ; but 

 in those of varieties long domesticated it is less apparent, the distinctions bctwe«]ji 

 the parents themselves being less fixed, and less clearly marked. 



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