HARDENING AND ADAPTATION 



average, the waves will go no higher than the 

 point of greatest hardiness. Thus, as the work 

 progresses, the plants which now and then 

 show peculiar hardiness beyond the normal are 

 chosen to carry forward the tests. From these 

 very hardiest ones, after long breeding and 

 selection come the ones which are not only to 

 unite the desirable qualities of their forbears 

 but which are to be fitted for their new envir- 

 onment." 



But in addition to hardening plants against 

 all these — sun and ice and drought and rain, — 

 they must be hardened for shipping and allied 

 purposes. Mr. Burbank may have a fruit, for 

 example, which matures early, is of a very 

 desirable character aud would sell well at a 

 long distance from its point of production. But 

 it is too soft — it will not stand shipment. So 

 he puts it through a long course of training, so 

 to speak, and, when he is through with it, it will 

 bear the long shipment and come out at the 

 end of the journey as fine as when it started. 



In the production of the prune, the outer 

 skin has an important bearing upon the suc- 

 cess of the industry. After the prunes have 

 been gathered and graded in size, they are 



201 



