PROBLEM 37 



63 



Number 

 of Peas 



Sprouted 



1st 



Day 



2nd 



3.1 



4th 



Sth 

 6th 



7ft 

 8th 

 9th 

 10th 



Problem 36: To show that food is needed by the embryo in 

 order to grow. 



Materials. — Growing pea and bean seedlings. 



Method. — We have already found that beans contain a supply 

 of food for the young plant. Test peas to see if food is also pres- 

 ent in the cotyledons. After the peas and beans have begun to 

 germinate remove the cotyledons and place them under favor- 

 able conditions for continued growth. What happens? Allow 

 bean seedlings to grow to a height of an inch, then remove both 

 cotyledons from some, one cotyledon from others, and leave others 

 with both cotyledons for controls. Which grow most rapidly ? 



Conclusion. — What do you conclude from these results? . 



Problem 37: Is any part of the air necessary for combusti$k, ? .jy 

 (Demonstration.) <£* J^ ^ 



NOTE. — We have seen that seeds use up food in order to grow and^that Jfeed^v* 

 grow only in the presence of air. We must now study the air in ordej|(Jo find wh: " 

 there is in it that enables seeds to use food and release the enera^^eol^sarx^r 

 growth. 



