THE MICROSCOPE AND PLANT LIFE 



lily have all their pores on the upper side. There 

 is a reason for this; the pores are likely to become 

 filled with dust, being on the lower side they are 

 protected somewhat; fiat leaves, by their shape, 

 afford no protection and floating leaves must have 

 their pores on the upper surface to obtain air. 



There are many other interesting things we may 

 learn about leaves, with the help of our microscope. 

 The cabbage leaf is quite smooth, but if we are 

 observant we shall have noticed that sometimes each 

 leaf appears as though it had been powdered, it has 

 a decided bloom. The bloom does not appear on 

 the leaf for ornament but for a purpose. It is a 

 waxy substance and it prevents the leaf from losing 

 moisture too quickly in dry weather. This is very 

 important for the plant; if the moisture taken up 

 from the soil were lost in the air too quickly by the 

 leaves, the plants would wither and eventually die. 

 It is not all plants which can wear a protective 

 covering when danger threatens, most plants have 

 either no protection or are permanently protected. 

 There is a large class of plants with folded or rolled 

 leaves; heather and marram grass belong to this 

 class. We must examine some of these leaves and 

 we shall find that all the pores are on the inside 

 of the leaf whether it be folded or rolled. The 

 reason for this is that moisture also escapes through 

 the pores and, when they are thus protected, it is 

 not carried off too quickly by drying winds. 



Many plants are protected, as far as their leaves 

 are concerned, at anyrate, by hairs. They take the 



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