OBSERVATIONAL LESSON XVII 3 



(3) Next, consider the thickness of the skin, the colour of the flesh, 

 and any other points that you may determine by cutting into the 

 potato. 



(4) Describe and sketch a second tuber which has just begun to 

 sprout, afterwards set it in a box full of earth which has a window 

 in the side. Put the tuber close to the glass where you can see the 

 sprouts. 



(5) Suspend a tuber over a jar containing water by means of a 

 strip of solder twisted round it. 



Note: Potatoes grow slowly, and further investigations will be 

 made in alternate lessons : this arrangement need not, however, pre- 

 clude additional observations from being made at shorter intervals. 



FIGURE 140. The developing "eye" of a 

 Potato tuber. 



