366 POPULAR SCIENCE MONTHLY 



success, Burbank has an advantage of true scientific character over his 

 fellow workers, and in it he makes a genuine contribution to scientific 

 knowledge of plant biology, albeit this knowledge is so far only proved 

 to be attainable and to exist. It is not yet exposed in its details and 

 may never be, however unselfish be the owner of it. For the going to 

 oblivion of scientific data of an extent and value equivalent, I may 

 estimate roughly, to those now issuing from any half dozen experi- 

 mental laboratories of variation and heredity, is the crying regret of all 

 evolution students acquainted with the situation. The recently as- 

 sumed relations of Mr. Burbank to the Carnegie Institution are our 

 present chief hope for at least a lessening of this loss. 



But let us follow our saved plum seedling. Have we now to wait 

 the six or seven years before a plum tree comes into bearing to know 

 by actual seeing and testing what new sort of plum we have? No; 

 and here again is one of Burbank' s contributions (not wholly original 

 to be sure, but original in the extent and perfection of its development) 

 to the scientific aspects of plant-breeding. This saved seedling and 

 other similar saved ones (for from the examination of 20,000 seedlings, 

 say, Burbank will find a few tens or even scores in which he has faith 

 of reward) will be taken from their plots and grafted on to the sturdy 

 branches of some full-grown vigorous plum tree, so that in the next 

 season or second next our seedling stem will bear its flowers and fruits. 

 Here are years saved. Twenty, forty, sixty, different seedlings grafted 

 on to one strong tree (in a particular instance Burbank had 600 plum 

 grafts on a single tree!); and each seedling-stem certain to bear its 

 own kind of leaf and flower and fruit. For we have long known that 

 the scion is not materially influenced by the stock nor the stock by 

 the scion; that is not modified radically, although grafting sometimes 

 increases or otherwise modifies the vigor of growth and the extent of 

 the root system of the stock. 



If now the fruit from our variant seedling is sufficiently desirable; 

 if it produces earlier or later, sweeter or larger, firmer or more 

 abundant, plums, we have a new race of plums, a ' new creation ' to go 

 into that thin catalogue of results. For by simply subdividing the 

 wood of the new branch, i. e., making new grafts from it, the new 

 plum can be perpetuated and increased at will. Simple, is it not? 

 No, it is anything but that in the reality of doing it; but in the 

 scientific aspects of it, easily understandable. 



Perhaps it may not be amiss to call attention to what must be the 

 familiar knowledge of most of us, and that is the fact that many (prob- 

 ably most) cultivated plants must be reproduced by division, that is 

 by cuttings, buds or grafts, and not by seeds, in order to grow ' true.' 

 For a piece of a cultivated plant will grow out to be very much 

 like the individual it was cut from, but the seeds will not, in most 



