SEED DISTRIBUTION 



151 



in which they may germinate, or because they are promptly 

 destroyed by birds or other animals, or by molds or other 

 organisms Avhich cause them to decay. 



139. Fruits. The term fruit in its most limited botanical 

 sense means the ripened ovary with its seeds and other con- 

 tents. In a grape there is nothing more than this. In a currant 



Fig. 140. Bract-winged fruits of linden 



/, fruits of linden, with a wing-like bract (6) by means of which they are blown 

 about by the wind. One half natural size 



or gooseberry, however, the thickened and fleshy calyx sur- 

 rounds the fruit proper and forms a part of what is usually 

 called the fruit by botanists. In many dry fruits, such as those 

 of Spanish needles (^Bidens, Fig. 135) and of the dandelion 

 (Fig. 136), the limb of the calyx forms some sort of hook, 

 spine, plume, or other appendage, and the whole is usually 

 spoken of as the fruit. Not infrequently the receptacle is 



