STUDIES OF SEED-PLANTS 219 



poppy and morning-glory have several cavities, each with 

 seeds, and are called capsules. 



Aggregates of Simple Dry Fruits. We commonly call a straw- 

 berry a " fruit," but botanically considered it is an aggregate 

 of simple dry fruits. The true fruits of a strawberry are the 

 hard bodies (each with a seed inside) which are set in the 

 surface of the berry. Each of these bodies develops from an 

 ovary, and is a single dry fruit or akene ( 213). The fleshy 

 mass in which the true fruits are embedded is the enlarged 

 receptacle. In a strawberry flower a large number of pistils 

 are set on a rounded receptacle. Flowers and berries picked 

 green and preserved in formalin will help to make the mode 

 of development clear. 



FIG. 69. The receptacle of the buttercup flower bears many simple pistils 

 and each develops into a simple dry fruit (akene). & is a section of a 

 flower showing the globular receptacle (white center). 



The flower of buttercups produces a similar mass of simple 

 dry fruits (akenes), but the receptacle does not become as 

 much enlarged as in the strawberry. 



A fig develops from a flower which has numerous pistils on 

 its receptacle, as in the case of the strawberry. And in both 

 cases the edible part is from a receptacle, but in the fig flower 

 it is concave, whereas that of the strawberry is convex. As 

 a result of this difference in shape of the receptacle, the fruits 

 of the numerous small pistils (the hard grains) are on the 

 inside of the ripened fig, but on the outside of the straw- 



