68 GERMINATION OF SEEDS 



so that they may have the same heat conditions, and remove 

 the box cover at night or in a closet by day so that the air 

 supply may be ample. After three days notice the result. 

 These seeds have had the same amounts of water, air, and 

 heat. The only difference has been the light. Does light 

 stimulate or hinder growth of seeds ? 



Conclusion. State your inference as to the effect of 

 light on germination. 



Note. Another method of making this experiment is to plant 

 seeds in a pan. Invert a flowerpot over some of them, having first 

 closed the hole in the bottom of the flowerpot. Press the rim well 

 down into the soil to exclude light. Air will enter through pores 

 in the flowerpot. After the seeds outside have begun to sprout, 

 remove the flowerpot to note the difference. 



52. THE FATE OF COTYLEDONS 

 Object. To find out the fate of the cotyledons. 

 Apparatus. An oblong box, soil or sawdust, and kidney beans. 



Method. Plant the beans in lots of three or four at inter- 

 vals of two days, beginning at one end of the box. Set the 

 box in a locality favorable for germination and growth. 

 At the end of three weeks make a careful study of the crop. 

 What has become of the cotyledons? How do the youngest 

 plants compare with the oldest ones in size and the appear- 

 ance of the cotyledons ? What does this prove as to the use 

 of cotyledons ? 



Conclusion. State the results of this experiment. 



53. THE FATE OF COTYLEDONS 

 Object. Same as in Experiment 52. 



Method. Repeat Experiment 52, using squash seeds 

 instead of beans. 



