24 



THE BOOT, OB DESCENDING AXIS, 



112. The fruit. After the flower has fulfilled its office, the do- 

 ciduous parts fall away, and the remaining energies of the plant arc 

 directed to the development of the pistils into the perfect fruit. Let U3 

 illustrate this doctrine by tracing out 



113. A view op the organs op tue pjeont, for example, (r) The root with 

 its numerous fibers and fabrillce (some fibers tuberous) continues the axis downward, 

 and ($) the stern upward. The leaves (a) approaching the summit, gradually loso 

 their characteristic divisions, and at length become simple bracts, (b) still undoubted 

 loaves. Next by an easy gradation they appear as sepals (c, d, e,) in the calyx, the 

 outer envelope of the flower, with stalk expanded and blade contracted. Then by 

 a somewhat abrupt transition they pass into the delicate and highly colored petals 

 of the corrlla (/ g.), still retaining the essential marks of the leaf. To tho corolla 

 uext succeed those slender organs called stamens (in, n\ known to bo altered 

 leaves from the fact of their being often converted into petals (i, h). Lastly the 

 pistils (»,) destined to bear the seeds, two or more central organs green in color, are 

 each the result of the infolding of a leaf, tho mid-vein and united edges being ye*, 

 discernible. 



CHAPTER IV 



THE EOOT OR DESCENDING AXIS. 



114. Definition. The root is the basis of the plant and the princi- 

 pal organ of nutrition. It originates with the radiclo of the seed ; the 

 tendency of its growth is downward, and it is generally immersed in 

 the soil. 



115. Diagnosis. Roots are distinguished from stems by their downward di- 

 rection, by the presence of absorbing fibers, (fibrillee), and by the absence of 

 color, pith, buds, leaves, and all other stem-appendages. 



116. Office. The two important offices 

 in vegetable life which tho root is designed 

 to fulfill, are obvious to every one, viz., to 

 support the plant in its position, and to 

 imbibe from the soil the food and moist- 

 ure requisite for its growth. How well 

 God has adapted its structure and in- 

 stincts to this twofold purpose observa- 

 tion is continually showing. 



117. The leading propensity of the 

 boot is, to divide itself into branches, and 

 its only normal appendages arc branches, 

 branchlets, fibers and fibrilla?, which are 

 multiplied to an indefinite extent corres- 



ta, «. Extremity of a rootlet of maple ponding with the multiplication of the 



with its flbrills and spongiole (magni- ^ t • . &hov ^ y^ ftt oncc 



fled 50 diameters.) ' ° ' ' 



