WOOD'S CLASS-BOOK OP BOTANY. XVU 



709. Where is the cambium layer found ? "What is it ? 



710. Why is it called the generative layer ? 



711. Why is the growth of Exogens unlimited? 



712. Why is the bark most sought in medicine, etc. ? 



713. What of a cross-section of an endogenous stem ? 



714. Explain particularly its structure. 



715. As to these bundles of what does each consist ? 



717. Has the Endogen a true bark ? Why does it split with difficulty ? 



718. Why are these plants called inside-growers, or Endogens? 



719. Why is the caudex of the palmetto, etc., often smaller at base? 



720. In what plants is the acrogenous structure found ? Why are they so 



called, i. e., point growers ? 



721. How does a cross-section of one of them appear? (Fig. 600.) 

 Here describe the figures 595 and 596. 



722. What is the rank of the mass-growers ? What is their only tissue ? What 



semblance of stems have they ? 



724. What can you say of the flbrilla? of the root ? (See the fig.) 



725. What may be said of the pileorhiza ? Show it in the figures. 



726. How does the root grow, and penetrate the soil ? 



729. What is the substance of the veins ? 



730. How many layers of the parenchyma are there ? When are the two 



alike, and when unlike ? 



732. What is the normal place of the stomata ? How in floating leaves ? 



733. What is the condition of the chlorophylle ? 



734. The vessels of cienchyma where, and of what use ? 



Explain fig. 604, and show the parts, as the epidermis, the two layers, 

 chlorophylle, spiral vessels, stomata, etc. 



CHAPTER V. 



736. What inquiries are we now to start ? 



738. What problem remains unsolved ? What phenomena do we refer to 



the vitality of the plant ? 



739. What is the lowest form of life? Whence does it spring? 



740. How prove that the vegetable kingdom is subordinate ? 

 742. In what steps does the process of vegetation consist ? 



What are the vital phenomena included in vegetation ? 



744. What two kinds of organic matter make up the cell ? 



Write out the symbols of these two. Which resembles animal matter ? 



745. What does the cell imbibe ? From what fluid ? 



746. What chemical decomposition ensues ? What becomes of the water 



formed ? What of the cellulose? 



747. How is chlorophylle formed ? What becomes of the excess of the 



cellulose ? What globule within a globule ? 



749. What becomes of the excess of protoplasm ? 



750. What per cent, of gluten and starch in wheat ? Why is extra flour 



deficient in gluten ? 



751. Can a plant consist of a single cell? Give an example. 



752. Describe the two modes of cell growth. 



753. How is growth distinguished from reproduction ? 



754. What is the embryonic vesicle ? Its origin ? Its destination ? 



755. How does it receive its impulse in this direction ? 



756. Trace the growth of the pollen grain after it falls on the stigma. 



757. Trace the course of the pollen tube, and in fig. 607. 



758. Show the process of growth in the fertilized cell, and in fig. 608. 



759. How does Schleiden's view differ from the above ? Explain fig. 609. 



