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In every seed there is to be distinguished, 1, the 

 organ of nourishment ; 2, the nascent plant, or the 

 flume ; 3, the nascent root, or the radicle. 



In the common garden bean, the organ of nour- 

 ishment is divided into two lobes called cotyledons ; the 

 plume is the small white point between the upper 

 part of the lobes ; and the radicle is the small curved 

 cone at their base.* 



In wheat, and in many of the grasses, the organ 

 of nourishment is a single part, and these plants are 

 called monocotyledonous. In other cases it consists of 

 more than two parts, when the plants are called poly- 

 cotyledonous. In the greater number of instances, it 

 is, however, simply divided into two, and is dicotyle- 

 donous. 



The matter of the seed, when examined in its 

 common state, appears dead and inert ; it exhibits 

 neither the forms nor the functions of life. But let 

 it be acted upon by moisture, heat, and air, and its 

 organized powers are soon distinctly developed. The 

 cotyledons expand, the membranes burst, the radicle 

 acquires new matter, descends into the soil, and the 

 plume rises towards the free air. By degrees, the 

 organs of nourishment of dicotyledonous plants be- 

 come vascular, and are converted into seed leaves, 

 and the perfect plant appears above the soil. Nature 

 has provided the elements of germination on every 

 part of the surface ; water and pure air and heat are 



* Fig. 13, represetits the garden bean, aa, the cotyledons, b, the plume, b f the 



radicle, 



