64 GERMINATION OF SEEDS 



Note. To be sure that no air remains in the flask let the gen- 

 erator work for some time after several test tubes of hydrogen have 

 been taken and tested for hydrogen. 



Suggestions. 1. Make an assortment of seeds and ar- 

 range each kind in as many different positions as possible; 

 for example, hilum upward; hilum downward; hilum to right, 

 seed on edge; hilum to right, seed on side; etc. 



Germinate the seeds. Make sketches representing the va- 

 rious turnings and twistings which the hypocotyl is compelled 

 to make in order to get into right relation to the soil. 



2. Make another assortment, selecting seeds of various 

 sizes, and plant five or six of each size, varying the depths 

 of each. After one or two weeks observe results. Has 

 depth of planting any relation to the size of seeds ? 



3. Compare old seeds with fresh ones of the same kind in 

 their ability to germinate. How does age affect vitality of 

 seeds ? 



48. RELATION OF DEPTH TO GERMINATION 



Method. Arrange a series of flowerpots containing soil. 

 Plant seeds in them as follows : 

 Pot I, five peas on the surface. 

 Pot II, five peas one inch deep. 

 Pot III, five peas two inches deep. 

 Pot IV, five peas three inches deep. 

 Pot I, five clover or alfalfa seeds on the surface. 

 Pot II, five ditto one inch deep. 

 Pot III, five ditto two inches deep. 

 Pot IV, five ditto three inches deep, 

 five ditto \ inch deep. 



Pot V 



five ditto | inch deep, 

 five ditto f inch deep. 



