GLIMPSES IXTO PLAXT-LIFE 



If we hold a leaf up to the light we see a 

 network of veins, and it is by their help the leaf 

 becomes a broad expansion of tissue, so exposed 

 that it gets the fullest possible benefit from the 

 sunlight and air. This fibrous 

 network gives strength to the 

 leaf, and answers to the bones 

 in animal structure. 



The fibro-vascular bundles, 

 which we see in the stem, go 

 up through the petiole, and 

 branch f)ut in a beautiful and 

 regular manner. We may ob- 

 serve this arrangement very 

 clearly in a skeleton leaf, the 

 mid-rib forming a backbone to 

 the whole structure, while the 

 smaller veins tend off to the 

 edge of the leaf, and then 

 overlap so as to form a 

 system of girders supporting the edge, and pre- 

 venting the wind from tearing the delicate tissues 

 into shreds. 



The arraneement of leaf network is called 



NKTTEI) VEINS. 



