152 Science of Plant Life 



7. Why are plants absent from sea beaches and from the beaches of large 

 lakes? 



8. Why do trees along streams have their longest branches out over the water ? 



9. Why do trees along streams frequently lean outward over the water? 



10. Why do trees on steep hillsides have their shortest branches toward the 

 hiU? 



11. What are the most favorable environmental conditions for the growing of 

 rice, celery, onions, dates, bananas, sugar cane, guayule, sisal, tulips, and 

 pecan trees? 



12. How do the plants and fruits of blackberries and dewberries grown in 

 bottom lands differ from those grown on dry hillsides? Why? 



