CHAPTER XIV 



CORK AND BARK 



TF we take a very thin crosswise slice of any 

 ■*■ young woody stem and look at it through a 

 powerful microscope, we shall see near the edge 

 a ring of cells which look different from all the 

 others. 



Most of the cells of the wood and pith are 

 round or oval, but these are square or oblong. 

 Most of the cells contain life jelly, but these are 

 empty. Most of the cells have colorless walls, 

 but these have brown walls. The oblong, empty, 

 brown-walled cells are cork. 



Perhaps we are accustomed to think of cork- 

 making as a very exceptional accomplishment 

 among the trees — an exclusive business carried 

 on by the Spanish branch of the oak family only. 



In fact, all trees make cork, all contain it, and 

 all need it. The little seedling has to begin cork- 

 making almost as soon as it begins growing. 



Cork is just as necessary in the woods as it is 

 in the medicine chest, and is useful for the same 

 reason — because no fluids, gases, fumes, or 

 vapors can get through it. 



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