GERMINATION OF SEEDS 



61 



in a warm place, as upon a desk where the temperature is 

 never excessive. Put C upon a hot radiator or in an oven. 



After five days bring 

 the preparations together 

 and compare the results. 



Do the seeds exposed to 

 the cold grow ? 



How about those in the 

 warm place and those in 

 the hot place ? 



Now remove all three 

 preparations to the same 

 warm location and allow 

 them to remain for three 

 days longer. Do the seeds 

 in A and C grow? Does 

 the cold hinder growth or kill the embryos ? 

 kill or merely hinder? 



Conclusion. State your inference as to the effect of 

 heat in making seeds sprout, also the amount necessary 

 and the effect of extreme heat and cold on germination. 



Query. In buying seeds for planting is it advisable to 

 purchase " sun-dried " or " kiln-dried " seeds? Why? 



45. THE AIR FACTOR 



Object. To find out how to make the embryo plant 

 begin to grow. 



Apparatus. Two wide-mouth bottles, sawdust, and seeds. One 

 of the bottles having a cork so that it may be tightly stoppered. 



Method. Plant the seeds in damp sawdust, packing them 

 in quite tightly to exclude as much air as possible. Then 



FIG. 16. Effect of heat. 



Does the heat 



