THE FRUIT 



189 



of a rather thin-skinned, one- to several-celled, fleshy ovary 

 and its contents. In the first three cases above mentioned 

 the calyx forms no part of the fruit, but it does in the last 

 two, and in a great number of berries. 



The gourd-fruit and the hesperidium, such as the orange 

 (Fig. 1-41), lemon, and lime, are merely decided modifica- 

 tions of the berry proper. 



231. Aggregate Fruits. — The raspberry (Fig. 142), 

 blackberry, and similar fruits consist of many carpels, each 



I II III 



Fig. 142. I, Strawberry ; II, Raspberry ; III, Mulberry. 



of which ripens into a part of a compound mass, which, 

 for a time at least, clings to the receptacle. The whole 

 is called an aggregate fruit. 



What is the most important difference in structure 

 between a fuUy ripened raspberry and a blackberry? 



232. Accessory Fruits and Multiple Fruits. — Not infre- 

 quently, as in the strawberry (Fig. 142), the main bulk of 

 the so-called fruit consists neither of the ripened ovary 

 nor its appendages. Such a combination is called an 

 accessory fruit. 



Examine with a magnifying glass the surface of a small unripe 

 strawberry, then that of a ripe one, and finaDy a section of a ripe 



