QUESTIONS ON 



CHAPTER II. 



662. What is the simplest possible form of vegetation ? 



663. What constitutes a tissue ? Name the four tissues. 



664. What the form of the cells of Parenchyma ? Classify them. 



666. What the form of the cells of Pleurenchyma ? Two varieties. 



667. In what trees do we find the pitted cells ? What is fig. 579 ? 

 Explain this beautiful appearance by fig. 579 bis. 



668. What is trachenchyma ? How are these tubes made ? 

 Show the structure of dotted-ducts in figs. 566, 576. 



671. Office of cienchyma ? What their nature ? 



673. What is said of the intercellular passages? 



674. Give, finally, the import of the cell. 



675. How is elevation of rank in plants indicated ? 



CHAPTER III. 



WHAT does the " epidermal system " include ? 



676. What is the office of the epidermis ? What its cells? 



678. What are the stomata ? When are they open, and when closed ? 



679. How many are found in the space of one square inch ? 

 Point out the stomata in the figs. 582-586. 



681. What is said of the structure of hairs ? 



682. What is the office of glands? What varieties are there? 



683. Describe the mechanism of the sting, in fig. 591. 



684. How do prick ] es differ from spines ? Describe the figures. 



CHAPTER IV. 



685. What does the " ligneous system" include ? 



686. Of what kind of tissue does the young rootlet consist ? 



687. What is the early tissue of all new growths ? 



688. What changes occur in the rootlet ? 



689. How is the increasing demand for moisture met ? 



690. Name the four grand divisions of plants. 



691. Describe a cross-section of the stem of an Exogen. 



692. Describe the pith ; its composition, contents, etc. 



693. Where do we find the medullary sheath ? What are its vessels? Its 



connections ? Its office ? 



694. Of what does the wood consist ? How much grew the first year ? 



How much each successive year ? 



695. Whence is the distinction between the annual wood-circles ? 



697. The alburnum and duramen how distinguished ? 



698. Which is the living wood? How does it become duramen ? 

 Which is valuable as timber ? 



699. What has perished in a hollow tree ? 



700. Name the three layers of the bark. 



701. The liber of what tissues? Whence is its toughness? 



702. What is the green bark ? What its structure ? 



703. The brown bark what are its varying colors? What is its tissue? 



How is it in the cork oak? 

 705. Define the medullary rays. What is their structure ? 



707. Why are they called the silver grain ? Show it in figs. 597, 598. 



708. What good purpose do they serve ? 



