FOLIAGE. 147 



Everything bends ; the leaves turn about, and rippling 

 air-currents pass along their surfaces, so that no harm 

 is done. Amongst the worst sufferers from wind are 

 Coniferae which are both in growth and appearance 

 stiff and rigid, the leaves especially having very little 

 pliability. 



The methods of mechanical support shown in leaves 

 deserve far more attention than has ever yet been paid 

 to them. The Red or White Campion has a round stem, 

 from which pairs of leaves spring. When the stem 

 is held on a level with the eye against the light, the 

 resemblance of these two curving leaves to arches 

 springing from the top of a pillar is very close indeed. 



The under surface of the leaves of many common 

 plants shows a dense network of prominent veins, which 

 gradually become thinner, and less prominent, towards 

 the tip and edges. In some cases, when the leaf is 

 held up in such a way that it is above the eye, it 

 resembles in an unmistakable manner the fretwork often 

 seen in the arched roof of churches ; but it is of an 

 infinitely more delicate and finished appearance. The 

 thickness of the veins at the base is obviously very 

 necessary. From a mechanical point of view the 

 beauty of the arrangement in leaves is best judged 

 from a comparison of two attempts by mankind to 

 attain a similar result. A mason's crane and an 

 umbrella, when compared with the leaf of the Lime or 

 of the Pennywort, appear exceedingly roughly made. 

 The curves of these leaves remind one sometimes of 

 stone bridges, or of Norman, Byzantine, or Gothic arches 

 of various kinds. Very often the shape of the curve 

 varies in the same leaf. It is low and gentle in the 

 main rib, but becomes much steeper or more Gothic in 

 the lateral ones. The Common Bracken is a very 



