THE REASON WHY. 293 



' For the earth bringeth forth fruit of herself; first the blade, then the ear, 

 after that the full ear in the corn." MABK v. 



CHAPTER LX. 



1167. W hy do some plants droop, and turn to the earth 

 after sunset ? 



Because, when the warmth of the sun's rays is withdrawn, they 

 turn downwards, and receive the warmth of the earth by radiation. 



1167* Why does the young ear of corn first appear 

 enfolded in two green leaves ? 



Because the light and air would act too powerfully for the young 

 ear; two leaves therefore join, and embrace the ear, and protect it 

 until it has acquired strength, when they divide, and leave the ear 

 to swell and ripen. 



1168. Why are the seeds of plants usually formed within 

 the corollas of flowers ? 



Because the petals of the flowers, surrounding the seeds, afford 

 them protection until they are ripened, when the flower dies, and 

 the petals fall to the ground. 



1169. Why does the flower of the poppy turn down during 

 the early formation of seed? 



Because the heat would probably be too great for the seed in its 

 early stage. The plant is therefore provided with a curious curv6 

 in its stalk, which turns the flower downward. But when the 

 seeds are prepared for ripening, the stalk erects itself, and the 

 seeds are then presented to the ripening influences of the sun. 



1170. Why have plants of the pea tribe, a folding blossom 

 called the " boat," or " keel?" 



Because, within that blossom the pea is formed, and the shape 

 of the blossom is exactly suited to that of the pea which is formed 

 therein. The blossom is itself protected by external petals ; and 

 when the wind blows, and threatens to destroy the parts upon 

 which the seeds depend, the plants turn their backs to the wind, 

 and shelter the seed. 





