ACCESSORY, AGGREGATE, AND COLLECTIVE FRUITS 85 



way against the assaults of animals. The acidity or other 

 disagreeable qualities of most unripe fruits the persim- 

 mon for instance insures them pretty effectually against 

 being molested before they have had time to mature their 

 seeds, while in nuts and other indehiscent fruits, the pro- 

 tection afforded by their bony pericarp is frequently ree'n- 

 forced during the growing season by such appendages as 

 the bur of the chestnut and the astringent hulls of the 

 walnut and hickory nut. 



The adaptations for dispersal in dry fruits consist mainly 

 of wings and sails, like those of the maple, ash, thistle, 

 dandelion, etc., by which they are carried from place to 

 place by the wind or water; or of hooks and adhesive 

 hairs by means of which they attach themselves to the 

 coats of animals or the clothing of men, who are thus 

 made the involuntary, and often the unwilling agents of 

 their dispersal. 



PRACTICAL QUESTIONS 



1. To what class of fruits would you refer an ear of corn? of wheat? 

 a sycamore or a buttonwood ball? a hop? a raspberry? a bunch of 

 bananas? a pine cone? the fruit of the tulip tree and umbrella tree? of 

 the mallow? Indian turnip? 



2. Tell the nature of the individual fruits that compose each. 



3. Name some fruits that are adapted to be carried about by the 

 wind ; by water ; by animals. 



4. How is the watermelon fitted for seed dispersal? the squash? 

 fig ? hickory nut ? huckleberry ? pomegranate ? maypop (Passiflora in- 

 carnata)'! corn? wheat? oats? 



5. Could the last three survive in their present form without the 

 agency of man? 



6. Name all the plants you can think of that bear samaras and 

 winged fruits of any kind ; are they, as a general thing, tall trees and 

 shrubs, or low herbs? 



7. Name all you can think of that bear adhesive fruits, like the 

 cockle bur and beggar's ticks ; are any of these tall trees or shrubs ? 



8. Give a reason for the difference. 



9. Why is the dandelion one of the most widely distributed weeds 

 ;n the world? 



10. Why is it that appendages for protection and dispersal are con- 

 nected with the pericarp in indehiscent fruits and with the seeds in the 

 dehiscent kinds? 



