




148 THE BEHAVIOUR OF PLANTS 
where plants grow. It will be interesting then, when 
you come in the presence of plants, for you to endeavour 
to read from the plants themselves the varied stories 
which they can tell of the influence which light has on 
them. Where leaves are crowded together, you will 
often see that each 
leaf in the cluster 
takes a definite 
place, so that it will 
be m a good posi- 
tion to get the light. 
This position of the 
leaf is not taken of 
itself alone. It 1s 
because the light, 
acting on it, causes 
it to take up this 
position. Leaves 
thus often form 
Fig. 183. Cedar of Lebanon, strong light only what are called 
from one side of tree (Syria). - 999 
pieces of ‘* mosaic, 
as seen in the Fittonia (Fig. 102) cultivated in green- 
houses. In the woods or hedges you will have an 
Opportunity of studying many of these “ mosaics,” and 
it will be interesting for you to see if there is any dif- 
ference in the size of any part of the leaf which 
enables it better to take a favourable position in the 
