EXERCISE 17 



Object. To study the germination of the rye kernel 

 and the early growth and development of the rye plant. 



Explanation. The kernel of rye incloses a living plant 

 in the dormant stage. The germ is the living part of the 

 kernel from which the shoot and roots develop. When the 

 kernel or seed is placed in the soil under proper conditions 

 of moisture and temperature, it absorbs moisture and begins 

 to grow. The food for the young plantlet is furnished by 

 the endosperm. 



When the kernel of rye germinates, it sends out four tem- 

 porary roots. As the plant continues to grow it sends out 

 permanent roots. The depth at which the permanent 

 roots occur depends upon the condition of the soil. If the 

 rye is seeded at a medium depth, the temporary and per- 

 manent root system will develop at about the same place. 

 If the rye is seeded very deeply, the permanent roots will 

 develop above the temporary roots and near the surface of 

 the soil. 



Equipment. 1. Plants of rye one, two, three, and four 

 weeks old, seeded one inch deep. 



2. Plants of rye two and four weeks old, seeded three 

 inches deep. 



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