36 BOTANY. 



71. Result of the experiment. For some time all the plants grow equally 

 well, until the nutriment stored in the seed is exhausted. The numbers I, 3 

 and 4, in soil and nutrient solutions, should outstrip number 2, the plants in 

 the distilled water. No. 4 in the nutrient solution with iron, having a perfect 

 food, compares favorably with the plants in the soil. 



Exercise 1 7. 



72. Notes on the water cultures. When the water cultures are set up the 

 members of the class can take notes on them. Then from time to time for 

 several months the plants should be inspected and the members of the class 

 should keep a record of the results, and should not only compare the plants in 



Fig. 20. Fig. 21. Fig. 22. Fig. 23. 



In soil. Nutrient solu- Nutrient solu- In distilled 

 tion with iron. tion without water. 



iron. 

 Figures 20-23. Comparison of growth of pumpkin seedlings, all started at the same time. 



the different jars, but should compare them with the plants growing in the 

 soil which were planted at the same time. From these records let each pupil 

 write a complete account of the experiment. 



II. How PLANTS OBTAIN FOOD FROM THE SOIL. 



73. Plants take liquid food from the soil. From these 

 experiments then we judge that such plants take up the food 

 they receive from the soil in the form of a liquid, the elements 

 being in solution in water. 



