xviii QUESTIONS ox 



760. In the Coniferse, where does the pollen faU ? 



761. What is the state of the embryo in the mature seed ? What store is 



laid up for it? 



762. What chemical changes ensue ? What is diastase ? Dextrine ? 

 Whence is the yeast? The heat? The sugar? 



766. In the process of ripening fruits, what material is formed? 



767. Whence is the honey in the flower? What the use of the sugar ? 



768. Of what use is the honey to the plant? 



CHAPTER VI. 



770. WHAT the subject ? What is the most important office of the root ? 



771. Illustration, by a plant of spearmint, hydrangea, etc. 



772. What organs absorb the water in these cases? 



773. Illustrate this by a radish plant. 



774. In transplanting trees, what special care must be used ? 



775. What of the force of this absorption ? How may it be shown ? 



777. Name the two causes of the ascent of the sap. 



778. Illustrate capillary attraction by glass tubes. By a napkin. 



780. Illustrate endosmose by dried prunes. 



781. Illustrate by a bladder and long glass tube. 



784. Of what use to the vegetable is absorption ? Have the roots the 



power of choice ? Give examples. 



785. What other organs absorb ? What illustrations are given ? 



787. In what direction is the flowing of the sap ? 



788. How does it advance in the tissue of a Cryptogam ? 



789. In higher plants, what is noticed in the different tissues? 



790. What vessels and passages convey air only ? 



791. What seems to be the moving force which raises the sap ? 



792. Through what tissue does the sap chiefly ascend ? 



793. Through which layers, and why? 



794. What is the composition of the crude sap? 



795. How do you account for the issue of sap from the sugar maple in early 



Spring? What causes the flow to cease? 



796. How does the crude sap become the true sap ? 



797. Trace the distribution of this fluid as it returns from the leaves. 



798. Specify the places where this sap makes deposits. 



799. In what direction is the growth, from above or from below ? 



800. Illustrate this by the girdling process. Why does the tree die? 



801. Illustrate by a ligature. Illustrate by a wound in the trunk. 



803. What the effect of cutting a branch just below a node ? 



804. What of girdling a potato plant ? Fruit tree ? Why ? 



806. Where does the flow called rotation occur ? Describe it 



808. What is the process called transpiration ? It occurs where and when ? 



809. What other process depends upon it ? Does it convey away pure 



water only ? 



810. How much water did a sunflower transpire per day ? A cabbage ? 



811. Describe an arrangement for showing the quantity of transpiration. 



812. What do we understand by respiration in plants ? 



813. What experiment with an air-pump shows its importance ? 



814. Why does the tree suffer when its roots have been buried too deep ? 



815. Define respiration in plants. Where does it occur ? 



816. What does the vast extent of the respiratory apparatus show ? 



817. State in order the six facts given in relation to respiration. 



818. State carefully the two opposite phases of respiration. 



