CHAPTER XLIV. 



THE FRUIT. 



I. Parts of the Fruit. 



867. After the flower comes the fruit. With the perfection of 

 the fruit the seed is usually formed. This is the end towards 

 which the energies of the plant have been directed. While the 

 seed consists only of the ripened ovule and the contained em- 

 bryo, the fruit consists of the ripened ovary in addition, and in 

 many cases with other accessory parts, as calyx, receptacle, etc., 

 combined with it. The wall of the ripened ovary is called a 

 pericarp, and the walls of the ovary form the walls of the fruit. 



868. Pericarp, endocarp, exocarp, etc. This is the part of 

 the fruit which envelops the seed and may consist of the carpels 

 alone, or of the carpels and the adherent part of the receptacle, 

 or calyx. In many fruits the pericarp shows a differentiation 

 into layers, or zones of tissue, as in the cherry, peach, plum, etc. 

 The outer, which is here soft and fleshy, is exocarp, while the 

 inner, which is hard, is the endocarp. An intermediate layer is 

 sometimes recognized and is called mesocarp. In such cases 

 the skin of the fruit is recognized as the epicarp. Epicarp and 

 mesocarp are more often taken together as exocarp. 



In general fruits are dry or fleshy. Dry fruits may be 

 grouped under two heads. Those which open at maturity and 

 scatter the seed are dehiscent Those which do not open are 

 indehiscent. 



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