322 THE LIFE OF THE PLANT 



actual organism, will no more be puzzling ; it will be a 

 question of time and selection. This explains why 

 naturalists hail Darwin's theory as the crowning of 

 the stately structure of modern physiology. It really 

 offers the key to the solution of the problem of the 

 origin of organisms, gives a reason for their perfection, 

 and solves the question we raised at the beginning of 

 this chapter. 



Having undertaken the study of the life of the plant, 

 we tried in our first chapter to analyse this complicated 

 phenomenon into its elements, by showing that a plant 

 consists of organs, that these organs consist of simpler 

 organs still — of cells — ^which in their turn present an 

 aggregate of certain chemical bodies. On the ground of 

 this analysis we then studied in the opposite, ascending, 

 synthetic order, first the properties of these substances, 

 then the life of the cell, the life of organs, the life of the 

 whole plant, and, lastly, in this concluding chapter the life 

 of the whole organic world. This apparently exhausts 

 our problem, brings us to the end of the course through 

 which I undertook to be your guide ; a long and toilsome 

 way, wearying at times, but not, as I hope, utterly fruit- 

 less. If for some of you ladies and gentlemen here 

 present, the plant ceases to be a lifeless object marked by 

 a Latin label, or an object exclusively of aesthetic enjoy- 

 ment, and becomes also a source of fuller intellectual 

 enjoyment : if by the discoveries of the microscope it 

 assumes enormous dimensions, and becomes sufficiently 

 transparent for you to look into the depths of the 

 numberless cells where you will perceive protoplasm — 

 the origin of all life — in ceaseless motion like the tide of 

 the sea ; if the same mental glance shows you the root 

 buried deep in the ground, imbibing its liquid food and 

 corroding the particles of the soil all along its course of 

 many miles : if the green leaf revives in your imagination 



