224 THE STUDY OF LEAVES 



AUTUMN LEAVES. 



In this study we must not omit to call the attention of 

 our pupils to the leaves while they are upon the trees to 

 delight our eyes with the autumn tints, to encourage pupils 

 to watch the changes upon individual trees, and generally 

 to cultivate appreciation of this aspect of nature. 



For indoor study, collect leaves newly fallen or about to 

 fall from the trees. 



Examine these so as to see the various colours whilst 

 the leaves are fresh. Select the prettiest for drawing and 

 colouring. Get from the children an expression of their 

 preferences. 



Next we may proceed to arrange according to the trees. 

 Compare a number of each kind, Sycamore, Poplar, Lime, 

 Horse-chestnut, etc. 



What colours does each kind exhibit ? Note, for example : 



Yellow in Poplars, Lime, Willow, Horse-chestnut, and 



many others. 



Brown in Oak, Beech, Service. 

 Eed in Mountain Ash (Eowan), Ehododendron. 



What parts of the leaf retain the green colour longest ? 

 Parts close to the veins frequently. 



What is the nature of the change taking place ? In 

 the simplest cases the change consists in a dissolution of 

 the chloroplasts, exposing a yellow pigment (xanthophyll) . 

 But there are usually complications owing to the forma- 

 tion and unequal distribution of other pigments. 



According to Miss Newbigin there are three main 

 factors : " (1) the disappearance of the chlorophyll green, 

 (2) the increasing prominence of the lipochromes, and (3) 

 the development of anthocyan. Other changes of minor 

 importance also occur. Thus the general effect is often 

 heightened by the dull brown colours assumed by the 

 leaves of such trees as the oak and the beech. These 

 colours are produced by the oxidation of the tannins of 

 which these trees contain such an abundant supply. These 



