Practice of Plant Breeding 



Amongst others who have found the selection of the 

 largest seeds to be an undoubted advantage are Arthur 3 

 (with peas), and Liebscher and Van Seelhorst. 4 



The heaviest seeds are not only most productive but 

 are also, sometimes at least, the most vigorous and 

 most enduring. 5 Just the same result has been dis- 

 covered in practical forestry. The finest and largest 

 seeds produced the strongest and most vigorous trees, 8 

 so that the importance of this very simple principle is 

 therefore manifest enough. 



Other experiments have shown that very large and 

 heavy potatoes produce descendants which inherit those 

 valuable characters. That was the result obtained by 

 Van Seelhorst between 1898 and 1903. 



There was a short time ago a crisis in the history of 

 Sea Island cotton in the United States. Some mysterious 

 disease suddenly increased and destroyed whole fields 

 of cotton. Some of the very best land seemed to be 

 hopelessly affected, and it looked as if the whole industry 

 would be destroyed. 



A minute fungus which infested the soil was the 

 author of this trouble. Mr. W. A. Orton was sent down 

 to the cotton-fields to try and deal with the situation. 

 He discovered here and there some individual stalwart 

 cotton plant which bore fruit in spite of the Fusarium 

 fungus. From their descendants he established a race 

 of Sea Island cotton which defied its attacks. 7 



Disease-proof pine-apples have also been obtained 

 and quite in the same way. 8 



Other valuable plants obtained in this simple manner 

 are the thornless oranges, violets with an enormous 

 number of flowers, and beetroots and sugar-canes with 

 a very high percentage of sugar contents. 9 



The most remarkable of all known cases of selection 

 is perhaps that of the seven-leaved clover. The cele- 



286 



