I9 2 FLOWER-LAND. 



stick to them they are taking up from the ground 

 their liquid food. In transplanting plants, therefore, 

 you should be careful to injure as little as possible 

 the ends and finer portions of their roots. This 

 taking up *by the roots of liquid food is called 

 "absorption" 



Now what becomes of this liquid food, or sap as it 

 is called ? It ascends from cell to cell, and from 

 vessel to vessel, passing through their thin walls up 

 through the stem and branches to the leaves. 1 " But 

 the plant takes in largely through the leaves some 

 more food, which it absorbs from the atmosphere. 

 Great changes take place, and the sap with new 

 matter in it passes down again through cells and 

 vessels, forming new substances as it goes, and helping 

 the plant to grow. 



When you know more about chemistry, you will 

 be able to learn particularly what these changes are 

 which take place in the sap and substance of the 

 plant. I will only try and give you a general idea of 

 the means by which they are brought about. 



One of them is the getting rid of some of the water 

 of the sap. This takes place by evaporation from 

 those parts of plants which are exposed to the air, 

 and is called " transpiration" \ The water, in the form 

 of vapour, is breathed out or given off into the 



* cf. diffusion in the Appendix. 



t From the Latin " trans ," across, and " spiro," I breathe. 



