56 THE PLANT: A GENERAL EXTERNAL VIEW 



organic things which make life possible and presently become 

 the substance of life itself. Incombustible substances from 

 which no energy can be extracted are transformed by leaves 

 into combustible substances, stored richly with that energy 

 which the leaf has caught from the light. All food, as we 

 have defined it, is organic, and photosynthesis is the one 

 great process of nature by which organic substances are 

 made out of inorganic ones. 



1 8. Reproduction. Under reproduction we may in- 

 clude all those processes which have to do with the main- 

 tenance of the life of the race. This would include the 

 care of the young. In man it might be taken to include 

 the education of the young, and all those other things 

 which are designed to .make the next succeeding genera- 

 tion better than the present one. 



No individual, plant or animal, can avoid responsibility 

 for reproduction. Nature makes reproduction the highest 

 duty of the individual ; in fact she seems to design the 

 individual life as a means to that end even more than as 

 an end in itself. When we think of the life of the race, 

 individuals seem almost like insignificant beads upon a 

 precious golden chain. The golden chain is the unbroken 

 thread of life which passes through the individuals and on 

 to other generations. For a time this precious thread is 

 in the keeping of the individual; his highest duty to 

 nature is to pass it on untarnished. 



As we grow older, we realize more and more the small 

 importance of our own life as compared with the life of 

 the race. We find that even to ourselves we are not so 

 important as the good we may be able to do is important. 

 We find that even to ourselves we seem valuable only as 



