302 LUTHER BURBANK 



be a uniformity of chemical composition between 

 the two that might be supposed to amount almost 

 to identity; particularly after the cion has been 

 in place for a term of years, and has grown from 

 a tiny twig to a large branch or a complete tree. 



Yet, in point of fact, there is abundant evi- 

 dence that the cion maintains its original identity 

 of character from first to last. This may be more 

 readily understood when we know that all plant 

 food is developed within the foliage. To be sure 

 the roots supply water, the universal solvent and 

 transportation agent of all life, and small quan- 

 tities of certain minerals and organic substances 

 in solution, but these are not digested for assimi- 

 lation as plant food until combined with carbon 

 dioxide which is transformed in the leaf cells 

 under the influence of the active rays of light, 

 first into fruit sugars and by later transformation 

 to cane sugar but of tener to starch, a more stable 

 form of food substance, in which form it is most 

 commonly stored in seeds, bulbs, tubers or en- 

 larged roots or stems, or to wood and less often 

 to various other substances used in the economy 

 of plant life and quite often useful to animal life 

 and to the industrial life of man. These trans- 

 formations are presented to us in the various food 

 products and the numerous gums, rubber, color- 

 ing materials, drugs, oils, and perfumes. 



