176 THE SURVIVAL OF THE UNLIKE. [vi. 



of propagations, many of the variations induced by soil 

 and methods of cultivation are likely to be perpetuated. 

 Careful propagators select young plants from those por- 

 tions of the plantation which produce what they consider 

 to be the ideal berry, but as no two propagators have the 

 same ideal berry in mind, there must arise a series of 

 divergences in the type. It is certain that there are dif- 

 ferent strains of Wilson in cultivation, as there are dif- 

 erent strains of the Crawford peach; and it is no doubt 

 this very diversity in the variety which adapts it so 

 readily to many soils and uses. I often wonder if the 

 original type of the Wilson, were, it to be again intro- 

 duced, would find so much favor as its modern progeny 

 does. No doubt every decade sees a new type of 

 Wilson strawberry. 



Thus all varieties of cultivated plants are moving 

 onward with unbroken front, filling in the unoccupied 

 places here and there, spreading into new territory by 

 virtue of new characters, some dropping out entirely in 

 the eternal shuffle for place and life. And because we 

 have observed the genealogy and have kept one name 

 for the parent and all its descendants, we have never 

 thought to question the identity of all the generations. 

 The Green Gage of to-day is not like the Green Gage 

 of two centuries ago simply because the names are the 

 same. Nature is a congeries of chains, one link giving 

 rise to another under the operation of eternal and inex- 

 orable law ; and when some of the links die and pass 

 away we notice the breaks, in our retrospect, and con- 

 ceive that evolution has been capricious. But the closer 

 we study the laws of organic life the more certain we 

 are that all present forms are the gradual outcome of 

 uniform and antecedent causes ; and I like to think of 



