148 



THE FRUIT 



A nut (Fig. 162) is larger than an akene, usually has a 

 harder shell, and commonly contains a seed which springs from 



a single ovule in one locule 

 of a compound ovary, which 

 develops at the expense of all 

 the other ovules. The chestnut 

 bur is a kind of involucre, and 

 so is the acorn cup. The name 

 nut is often incorrectly ap- 

 plied in popular language ; for 

 example, the " Brazil nut" is 

 really a large seed with a very 

 hard testa. 



183. The berry. This is a 

 generally fleshy fruit, which 

 usually does not split open. 

 Such berries as the tomato, 

 grape, and persimmon result 

 from the ripening of a supe- 

 rior ovary. Those of the gooseberry, currant, and many others 

 result from half-inferior or inferior 

 ovaries, and therefore a consider- 

 able part of the bulk of the fruit 

 is receptacle. The leathery- 

 skinned fruit of the orange family 

 is a true berry. 



The fruit of the apple, pear, and 

 quince is called a pome. It con- 

 sists of a several-loculed ovary, 

 the seeds and the tough membrane 

 surrounding them in the core, 

 inclosed by a fleshy edible portion 

 which makes up the main bulk of 

 the fruit. In the apple and the pear much of the fruit is 

 receptacle. 



Cross section of an orange 



a, axis of fruit, with dots showing cut-off 

 ends of fibro-vascular bundles ; p, par- 

 tition between cells of ovary ; S, seed ; 

 c, locule of ovary filled with a pulp com- 

 posed of irregular sacs full of juice ; 

 o, oil reservoirs near outer surface of 

 rind ; e, corky layer of epidermis. 

 After Decaisne 



FIG. 164. Peach. Longitudinal 

 section of drupe 



After Decaisne 



