216 SPRING BLOSSOMS. 



the growth of the plant is handed over to the 

 green leaves in the open sunlight. In fact, the 

 sole use of roots is to suppl}"- the leaves with proper 

 moisture, and with the very small quantity of 

 mineral matter and nitrogen compounds which the 

 plant requires for its full development. The main 

 work of feeding the whole herb is carried on by 

 the green foliage. 



This being so, it is easy enough to see that 

 plants are entirely dependent for support upon 

 their green leaves. During the summer-time these 

 leaves, expanded freely to the warm sun, are per- 

 petually engaged in manufacturing starches and 

 other raw materials for the future growth of the 

 ■whole vegetable system. To the outer eye, the 

 plant appears a stationary, motionless, and almost 

 lifeless thing ; but, if we could but watch with a 

 microscopic vision its unceasing processes of 

 change and development, we should see that it is 

 in reality a strange and busy natural laboratory, 

 where endless curious operations are for ever 

 taking place with marvellous rapidity in every 

 direction. The sap is circulating and moving 

 ceaselessly from cell to cell ; the green material in 

 the exposed surface is busily assimilating particles 

 of carbon from the surrounding air; the root is 

 supplying water and small quantities of other 

 necessary materials ; the digestive organs are 

 working up the whole by some subtle chemistry 



