66 MINUTE MARVELS OF NATURE 



increase in size, spaces form between them, until 

 we get the stem with leaves arranged symmetri- 

 cally round it at regular distances, as we see it in 

 the branch of any familiar tree. 



Of course there are many variations in leaf 



Fig. 44. Section of leaf of the deadly nightshade, showing 

 large palisade cells 



structure. For instance, Fig. 44 represents a 

 section through the leaf of the deadly nightshade, 

 the structure of which, on comparison with the 

 laurel leaf section, will be seen to differ by the 

 omission of the outer varnish layer and more con- 

 spicuously by the palisade cells occupying at least 



