34 LUTHER BURBANK 



So, we may fairly assume that it is only within 

 the comparatively recent period since the plum 

 was under cultivation that the development of 

 a race of sweet plums, which we now term 

 prunes, has taken place. 



JUST THE RIGHT SKIN TEXTURE 



As to the other characteristic prune trait, that 

 of developing a skin of such texture that it will 

 crack in precisely the right way when put into the 

 alkali bath, this may fairly be assumed to be an 

 even more recent acquisition. 



Yet here, again, we may assume that there 

 were ancestors of the plum that developed char- 

 acteristics of skin of which this is perhaps a remi- 

 niscence. And it is not very difficult to conceive 

 how this may have come about. 



The wild plum quite commonly grows along 

 watercourses and by lakesides. It may chance 

 that plums growing along the shores of the Med- 

 iterranean, or perhaps by some inland body of 

 salt water like the Dead Sea, were covered on 

 occasion with salt spray from dashing waves or 

 saturated with the brine when they fell to the 

 earth. 



In such case, varieties that chanced to en- 

 dure this treatment best would be the ones pre- 

 served, and in due course a race of plums having 



