809 LrTirFR BUBT^WK 



be « uniformity of chemical compoutioo bet we en 

 the two that might be suppoaed to amount almoat 

 to identity; {Mirticularly after the ekm haa been 

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

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



Yet in point of fact, there is abtmdant evi- 

 dence that the don maintaina its original identity 

 of character from first to last This may be more 

 readily undenlood when we know that all plant 

 food ia developed wUkm the foliage. To be sure 

 the roots supply water, the imirersal solvent and 

 transportation agent of all life, and sm5>^^ <t.in- 

 titles of certain minerals and onr^nir «< os 



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 oftener 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 leM 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. 



