24 



THE ROOT, OR DESCENDING AXIS. 



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

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

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

 illustrate this doctrine by tracing out 



113. A TtEW OP THE ORGANS OF THE p^oNT, for example, (r) The root with 

 its numerous ^6cra stoA fabi-illce (some fibers tuberous) continues the axis downward, 

 and («) the stem upward. The leaves (a) approaching the summit, gradually lose 

 their cliaracteristlo divisions, and a;t length become simple bracts, (6) still undoubted 

 leaves. Next by an easy gradation they appear as sepals (c, d, e,) ia 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 corolla (/ g^, still retaining the essential. marks of the leaf. To the corolla 

 next succeed those slender organs called stamens (m, -n), known to be altered 

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

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

 each the result of the infolding of a lea^ the mid-vein and united edges being yet 

 discernible. 



/ 



CHAPTEK IV. 



THE EOOT OB DESCENDING AXIS. 



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

 pal organ of nutrition. It originates with the radicle 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 abs,orbing 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 the 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 

 root is, to divide itself into branches, and 

 its only normal appendages are branches, 



. branchlets, fibers and fibrillse, which are 

 multiplied to an indefinite extent corres- 

 j2, a. Extremity of a rootlet of maple ponding with the multiplication of 'the 



r.r2m" """''''''''''"""'■ ''«*-«' t-g^' ^-> -»>-«• This at once 



