

VARIATION IN TRILLIUM GRAXDIFLORUM. 

 H. W. Britcher. 



To all those who have cultivated vegetable or flower gardens 

 it has probably been a matter of frequent observation that, in any 

 bed composed of plants all of the same sort, there have been 

 individual differences or variations. Some of the plants have 

 been more vigorous growers than others and have come to earlier 

 maturity. In some of the plants the flowers have been uniformly 

 of larger size or perhaps have shown a tendency to be double 

 or in some other wav differ from the flowers of the rest of the 

 plants. The horticulturist, growing plants in large quantities, 

 has a much wider field of observation. When he finds a plant 

 exhibiting a slight variation which he considers of value he 

 carefully saves the seed and from it raises another generation 

 of plants, some of which will show the variation in intensified 

 form. From such plants another generation is raised and the 

 process is repeated until the variation becomes fixed, that is, 

 until the desired character is present in all the plants raised 

 from the selected seed. This is known as artificial selection and 

 is one of the ways in which new and improved varieties are 

 produced. Propagation from sports, or plants in which vari- 

 ations become fixed in a single generation, is another method 

 and hybridization is still another. By these methods most of 

 our cultivated crops of the present day have been developed 

 or artificially evolved from, in most cases, pactically worthless 

 ancestors. In his book entitled "The Evolution of Our Native 

 Fruits," Professor Bailey says : "The American grapes have 

 given rise to eight hundred domestic varieties, the American 

 plums to more than two hundred, the raspberries to three 

 hundred and various other native fruits have a long cultivated 

 progeny." 



In "Animals and Plants Under Domestication" Darwin pre- 

 sented a vast amount of material on artificial selection, and in 



12 



