14 INTRODUCTION. 



eral aspect so obviously that the most hasty observer would 

 notice their relationship. So in the genus Pinus, no one would 

 hesitate to include the White Pine, the Pitch Pine, the Long- 

 leafed Pine (P. strobus, rigida, and palustris), any more than we 

 would fail to observe their differences. 



30. Thus individuals are grouped into species, and species 

 arc associated into genera. These groups constitute the bases 

 of all the systems of classification in use, whether by artificial or 

 natural methods. 



Review. 12. Three Kingdoms of Nature ? 13. A mineral ? Illustrate. 14. A plant ? 

 Illustrate. 15. An animal? 16. Define Physics. 17. Zoology. 18. Define Botany. 19. 

 Organography. Morphology. 20. Elementary Botany. 21. Physiological Botany. 22. 

 Systematic Botany. 23. Phytology. 24. Applied Botany. 25. Names. 26. Latin names. 

 87. A Species. Illustrate. 28. Varieties. 29. What is a Genus ? 



CHAPTER III. 



THE FOUR STAGES OP PLANT LIFE. 



31. In its earliest stage of life, the plant is an embryo sleeping 

 in the seed. It then consists of two parts, the radicle or rootlet, 

 and favplumule. Both may be seen in the Pea, Bean, or Acorn. 

 Besides the embryo, the seed contains also its food in some form, 

 provided for its first nourishment. 



32. At length the genial warmth and moisture of the Spring 

 awakens the embryo, and it begins to feed and grow. The radi- 

 cle protrudes the slender rootlet (fig. 2, r), which turns down- 

 ward, seeking the dark damp earth, avoiding the air and light, 

 and forms the root or descending axis. The plumule, taking the 

 opposite direction (fig. 3, p), ascends, seeking the air and light, 

 and expanding itself to their influence. This constitutes the 

 stem or amending axis, bearing the leaves. Thus the acorn 

 germinates, and the Oak enters upon the second stage of its 

 existence. 



33. At first the ascending axis is merely a bud, that is, a grow- 

 ing point clothed with and protected by little scales, the rudi- 

 ments of leaves. As the growing point advances and its lower 

 scales gradually expand into leaves, new scales successively ap- 

 pear above. Thus the axis is always terminated by a bud. 



