ROOTS 87 



75. ROOTS 



Object. To find out where the sap circulates in a root. 



Apparatus. Two large parsnips, a battery jar, and a pint of 

 water in which a small quantity of eosin has been dissolved. 



Method. Cut off the tip of one parsnip and place it 

 standing in a jar containing eosin solution. Let it remain 

 for two or three hours. Then remove it and make a section 

 from end to end. What region of the root has become 

 stained ? 



Dig out a cuplike hollow in the top of another parsnip 

 and fill it with eosin solution and let it stand. After three 

 hours rinse out the top and make a section as before. 



Does the sap circulate both ways or only one? In which 

 region ? 



Conclusion. State where sap flows in a root. 



Note. If anilin of two colors is used, one color in the battery jar 

 and the other in the cuplike hole at the top, it will be seen that the 

 upward and downward circulation is not in the same set of tubes. 



Beautiful sections can be made by using eosin and methyl green 

 as the anilin dyes. 



To the Teacher. If parsnips are treated in this way and then 

 sliced very thin on an ordinary cabbage cutter or with a carpenter's 

 plane, they may be dried under pressure between blotters and then 

 mounted between plates of glass and bound with passe partout 

 binding. Such mounts are useful in demonstrations and reviews. 



76. ROOTS 



Object. To learn the direction of growth in a root. 

 Apparatus. A plate of glass, blotting paper, germinated seeds. 



Method. Arrange the sprouting seeds upon a blotter 

 so that the roots point in the same direction. Cover them 



