i 



THE MICROSCOPE AND PLANT LIFE 



up to the light it appears green, but when light is 

 reflected from it, it appears reddish. 



From the under side of the cabbage leaf whence 

 we obtained our first specimen of chlorophyll, we 

 must now take another piece of skin. If we perform 

 the operation properly the skin will be colourless, 

 like a piece of thin parchment; any green colour 

 will show that we have torn off more than the skin 

 and we must make another attempt. Having 

 secured our piece of skin we place it in a drop of 

 water on a clean slide and examine it under the 

 microscope. We first notice that the skin is divided 

 up into a number of small areas called cells and 

 dotted here and there amongst the cells are several 

 oval bodies, containing chlorophyll. These oval 

 bodies are the pores through which the leaf breathes, 

 amongst other things. In the centre of each pore 

 there is a hole, at least there is if the pore is open, 

 for the two cells comprising the pore have the power 

 of opening and closing. 



It is interesting to try the same experiment with a 

 fern leaf and to notice that there are pores, very simi- 

 lar to those of the cabbage, but that the walls bound- 

 ing the cells of the leaf are irregular and that they 

 contain chlorophyll. We may try several other 

 leaves and also the upper and lower surfaces of 

 leaves, then we shall soon learn that, in leaves with 

 distinct upper and lower surfaces, there are far more 

 pores on the lower than the upper surface; leaves 

 like those of the iris have almost the same number 

 on each side, and floating leaves, like those of water 



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