260 PRACTICAL COURSE IN BOTANY 



2. Of what use to the plant is the hard stone of the drupe? (21.) 



3. Is the pulp of fleshy fruits agreeable to the taste before they are 

 ripe? After? What advantage is this to the plant ? (21.) 



4. Are the seeds of edible fruits, as a general thing, digestible or agree- 

 able to the palate ? 



5. Is this an advantage to man? To the plant? (21, 284, 285.) 



6. What are the most common fleshy fruits in autumn ? 



7. With what vegetative parts of the plant does the skin of many 

 fruits present correspondences ? Are these such as to indicate homology, 

 or analogy only, between them? (100, 118, 288, 289; Exp. 89.) 



8. Name six of the most watery fruits that grow in your neighborhood. 



9. Under what conditions as to soil, heat, moisture, etc., does each 

 thrive best ? 



10. Would a gardener act wisely to infer that because a fruit contains 

 a great deal of water it should be planted in a very wet place ? 



11. Which contains more water, the fruit or the leaves of the apple ? 



12. Why does not the fruit, when separated from the tree, wither as 

 quickly as do the leaves? (Exp. 91.) 



III. DRY FRUITS 



MATERIAL. Some easily attainable specimens of dry fruits are (1) nuts: 

 acorn, hickory nut, walnut, chestnut, pecan, filbert ; (2) pods : pea and bean 

 pods, capsules of larkspur, milkweed, jimson weed, cotton ; (3) grains : corn, 

 wheat, oats, rice; (4) akene: sunflower, thistle, dandelion, buckwheat, 

 clematis. 



293. Importance of dry fruits. Dry fruits are not in 

 general so conspicuous or so attractive as fleshy ones, but on 

 account of their great number and variety they offer a 

 wide field for study. They are also of great interest from an 

 economic point of view: (1) because they include the cereal 

 grains that furnish so large a portion of our food, and (2) 

 because the greater part of the troublesome weeds that infest 

 our crops are scattered by fruits of this class. 



294. Indehiscent fruits. - - These kinds are so simple that 

 it will not be necessary to give much time to them. Compare 

 an acorn, a chestnut, or a filbert with a ripe bean pod or with 

 a capsule of morning-glory. Try to open each with your 

 fingers ; which dehisces, 6r opens, the more readily ? Which is 

 indehiscent, having no regular way of opening ? How many 



