l8 THE CEREALS IN AMERICA 



A good illustration of unconscious improvement is to be 

 found in cabbage, kale, collard, palm borecale, Brussels sprouts, 

 kohl-rabi, ruta-baga and cauliflower. These all come from a 

 single, somewhat woody, branching perennial {Brassica olera- 

 cea Z.) which is to be found growing wild on limestone bluffs 

 in southwestern Europe. Some are a modification of the leaf, 

 as in the cabbage and kale, others of the stem, as kohl-rabi, 

 still others of the root, as ruta-baga, while in the cauliflower it 

 is the selection of the inflorescence that has caused the peculiar 

 modification. Some of these types have twenty or thirty varie- 

 ties, so that there are probably over one hundred distinct forms 

 from this one wild type. All of these forms are the result of 

 long and patient selection of variations that were considered 

 desirable by the gardener without any conscious attempt to 

 produce these specific forms. 



37. Examples of Definite Improvement. — The sugar beet ii 

 an illustration of systematic breeding to bring about a definite 

 improvement. In less than a hundred years of systematic 

 selection of individuals of known excellence, and by testing 

 their ability to reproduce the desired characters, the common 

 garden beet, with 6 per cent of sugar, has been transformed 

 into the sugar beet, which often contains from 15 to 20 per cent: 

 of sugar and is otherwise improved. 



By similar methods, wheat, flax, timothy and other farm 

 crops are being systematically bred for definite characters. The; 

 proper method to be employed will be discussed under the crop 

 in question. Much greater advance has been made with vege- 

 tables and other horticultural crops than with field crops. 



" At the present day species that have been cultivated for many years have 

 become, so to say, like wax in the hands of special growers, who mold them and 

 fashion them to their taste, obtaining the various modifications of shape, size, 

 flavor, etc., demanded by their patrons and the caprices of fashion."! 



The time will doubtless come when there will be many 

 breeders of pure strains of maize, wheat, timothy and other field 



i Henry L. De Vilmorin. E. S. R., Vol. XI, p. 6 



