500 HYBRIDS ARE DIFFICULT TO PRODUCE. 



not differing in any respect from the matrix; nor is the 

 effect different if a division or portion of the stigma be dusted 

 with either pollen separately, precaution being taken that 

 there shall be no possibility of admixture. The elective 

 affinity for the natural poUen makes the other completely 

 negative. 



After all his experience Gsertner was finally obliged to con- 

 fess that experiment shows a great, perhaps the greater portion 

 of plants not to be susceptible of hybridisation. Out of seven 

 hundred species submitted to nearly ten thousand distinct sets 

 of experiments only two hundred and fifty true hybrids were 

 raised. Allowing the possibility of repeated experiments 

 proving that union is possible in some cases where it has not 

 yet been obtained, the result is sufficiently striking, showing 

 especially when taken in conjunction with the large number of 

 failures where success has in some cases been obtained, not 

 only that the least portion of the vegetable kingdom is capable 

 of hybrid fecundation, but that as a general rule it is a forcing 

 of nature. It, moreover, seems to be a general rule that the 

 pollen of a species possessing a greater elective af&nity 

 neutralises the influence of that of one less closely allied in 

 that respect, as also does that of the matrix the fertility of the 

 pollen of another species. 



Those who occupy themselves in attempts at improving the 

 quality of cultivated plants should be aware of this ; namely, 

 that the real quality of either the fruit or the flower of a seed- 

 ling cannot be ascertained when they are first produced, for it 

 is only as plants advance in age that the secretions necessary 

 for the perfect production of either the one or the other are 

 elaborated. Of this fact the first produce of the Black Eagle 

 Cherry-tree afforded a striking example. A part of it was 

 sent, with other Cherries, to the Horticultural Society ; and it 

 was then, in the Fruit Committee, pronounced good for 

 nothing. It was so bad, that Mr. Knight, who raised it, would 

 most certainly have taken off the head of the tree, and employed 

 its stem as a stock, but that it had been called the property of 

 one of his children, who sowed the seed which produced it, and 

 who felt very anxiovis for its preservation. It has now become 



