170 TILLERS OF THE GROUND CHAP. 



parts. There were always a few three -partite 

 leaves, as well as four-, six-, and seven-partite ones. 



Perhaps somebody will say that five -leaved 

 clovers are not much use, especially for people who 

 do not believe in "luck." But is it not rather 

 interesting to know that with time and patience 

 we can make almost any plant we want ? 



These cases illustrate what can be done by simple 

 selection, accompanied by careful cultivation. Let 

 us take now another case to illustrate what crossing 

 does. Burbank has done a great deal of experi- 

 menting with the different kinds of lilies, which 

 are such favourite garden flowers. He wanted to 

 produce a number of new varieties, and to get 

 these he began in this way. He got, from all 

 parts of the world, nearly fifty kinds of lilies, all of 

 which had in his eyes some particular merit which 

 made them good, though not perfect, garden flowers. 

 These lilies were crossed and intercrossed in the 

 most elaborate way, a long series of experiments 

 being performed. 



The result was a large amount of hybrid seed. 

 This seed was sown, and finally as many as a hundred 

 thousand hybrid lily plants were produced. Two 

 acres of ground were planted out with these lilies, 

 and all were allowed to flower. The result of the 

 crossing was such that among these hundred 

 thousand plants almost every possible variety of lily 



