o12 ELEMENTS OF BOTANY. 
any of its countless forms, is sometimes called survival of the 
jittest, 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. 
