20 THE POTATO 



The sweet potato is another consideration and 

 is described in another chapter. 



It is possible that the change in temperature 

 each day, which approximates 30 to 50 degrees, 

 has something to do with the vitahzing of plants, 

 the same as man is apparently invigorated and 

 restored daily in these mountain districts where 

 such changes occur. 



