212 ELEMENTS OP BOTANY. 



any of its countless forms, is sometimes called survival of the 

 fittest, and sometimes natural selection. The latter name 

 means only that the outcome of the process just described, as 

 it goes on in nature, is much the same as that of the garden- 

 er's selection, when, by picking out year by year the earliest 

 ripening peas or certain kinds of the oddest-colored chrys- 

 anthemums, he obtains permanent new varieties. Natural 

 agencies, acting on an enormous scale through many ages, 

 may well be supposed to have brought about the perpetuation 

 of millions of such variations as are known to be of constant 

 occurrence among plants, wild as well as cultivated. 



