214 PRACTICAL LESSONS IN SCIENCE. 



with little stone fruits. In the case of the apple, pear and quince 

 the thick fleshy part is not the wall of an ovary but a thickened 

 calyx. 



Sometimes the wall of the ovary becomes thin like a mem- 

 brane, or hardens, or remains herbaceous, forming fruits, that 

 in some cases open at maturity for the escape of the seed, while 

 in other cases they remain closed, having the appearance of sim- 

 ple seeds, and are called akenes. The fleshy part of the straw- 

 berry is the softened end of the stem on which the flower stood 

 and the real fruits are ripened ovaries, usually called seeds, 

 scattered over its surface. The fruit of the sunflower, dandelion 

 and many others are akenes. In the case of wheat, corn and 

 other grains, the seed and ovary wall adhere so as to form one 

 body, so that a grain of wheat is a true fruit, called a caryopsis. 



Capsule or pod is the name for dry seed vessels that split open 

 at maturity. The pea-pod is a good illustration. Fruits were 

 designed to help in some way toward the reproduction of species; 

 in many cases they serve as storehouses of food to aid in the 

 growth of the young plant. And they are the most valuable 

 sources of food for man and domestic animals. 



