26 



HEROES OF SCIENCE. 



duces, and the decay of the plant have to be 

 studied. Then the uses of plants, medicinal and 

 as food, have to be treated. How they can be best 

 grown, and how plants are distributed over the 

 land at different heights, form other subjects ; 

 and the arrangement of plants in a classification 

 founded on the similarity of their most important 

 anatomical structures, and constituting what is 

 termed a natural system, is one of the most 

 necessary studies. 



