HYBRIDISING AND CROSS-BREEDING. 



101 



assume an alternate development which secures the same 

 end. 



Cross-Fertilisation and Fertility. Some experiments made 

 by Mr Williams go to prove that artificial fertilisation not only 

 improves the quality, but also increases the quantity of the seed 

 produced. For example, a flower of Victoria Regia fertilised 

 with pollen from another flower growing on the same plant 

 yielded four times as much seed as when left to become 

 naturally fertilised, and above one-half more than when care- 

 fully fertilised with pollen from the same flower; and the 

 result was still better by two-thirds when the flower was fecun- 

 dated with pollen from a flower of the same species growing on 

 another individual plant. 



Dean Herbert, writing in 1837 (see Herb. Am., p. 371), 

 remarks : " I am inclined to think that I have derived advan- 

 tage from impregnating the flower from which I wished to 

 obtain seed with pollen from another individual of the same 

 variety, or at least from another flower rather than with its own, 

 . . . and especially from an individual grown in a different 

 soil or aspect." To illustrate this, he mentions that he had nine 

 hybrid Hippeastra flowering in his stove, and being desirous of 

 blending these still further, the different flowers (stigmas) were 

 touched with pollen from their several neighbours and ticketed, 

 other flowers being touched with their own pollen. Almost 

 every flower that was touched with pollen from another cross 

 produced seed abundantly, and those which were touched with 

 their own pollen either failed entirely or formed slowly a pod 

 of inferior size, and with abortive flower-seeds. " It seems to 

 me that this circumstance may be analogous to the introduction 

 of a male from another flock or herd, which has been found 

 advantageous to the breed of domestic animals." 



Hybrids prove that their parents are nearly-related species, 



