The Leaf 105 



(b) For each child. 



Leaf bud of common or wild cherry, or horse- 

 chestnut just bursting into leaf. One of each of the 

 folloiving leaves: apple or pear, honeysuckle, haw- 

 thorn, beech, elm, rose or blackberry. (In each case 

 where an alternative is given the first named should be 

 used if possible.) Twigs of lilac and laurel (or ivy) 

 bearing leaves. Botanical pressing paper or blotting 

 paper. 



Do you remember that when we were speaking of 

 the way in which trees and all other plants live you 

 learnt that the green leaves are really a tree's lungs by 

 which it breathes and gets rid of unnecessary moisture ? 

 I told you also that with the help of the sunlight they 

 manufacture food for the tree in the form of starch. 

 Since both light and air are needed for these processes 

 a leaf has a broad flat blade which exposes to them as 

 large a surface as possible. This blade is so thin that it 

 would be very easily torn if it were not for the frame- 

 work of veins by which it is strengthened just as an 

 umbrella is by its ribs. The soft part of a leaf which 

 lies in between the veins is made up of tiny cells packed 

 together, each of which contains a number of round 

 green bodies which give the leaf its colour and are 

 responsible for making the starch. If a plant is grown 

 in the dark its leaves are sickly and white because 

 without light these green bodies cannot exist, but in a 

 healthy plant they are always there. One case may 

 occur to you which looks like an exception. How about 

 red leaves like those of the copper beech ? Even in 

 these the green is really there, but it is hidden by the 

 red colour of the outer skin. In some trees which like 



