SEEDS AND FRUITS 155 



Stories are current of seeds being taken from 

 mummy cases six thousand years old whicli showed 

 powers of germination, but such statements are not 

 authentic. Instances are known in which certain 

 species have lived three hundred or even four hun- 

 dred years, but these probably represent the limit 

 attainable by only a few plants. Ordinary forms, 

 such as wheat and corn, may not live longer than 

 fifteen or twenty years at the utmost, and the 

 seeds of nearly all cultivated plants begin to show 

 lessening powers of germination after a year. 

 Some are totally worthless the second year. 



210. Fi'uits. — In addition to the coats formed 

 around the seed the portions of the ovary in con- 

 tact with the seed are often developed in certain 

 ways of benefit or assistance in the protection, dis- 

 semination, or germination of the seeds. The seed 

 and. all of the parts of the ovary adhering to it 

 constitute a fruit. The study of the structure and 

 behavior of the fruit after the ripening of the seed 

 will therefore be of great interest. 



211. The cocoanut. — The fruit of Cocos nuci- 

 fera offers a most interesting object for the illus- 

 tration of the action and structure of the fruit of 



