THE ROOT. 35 



tached to the place of its growth. The root in its general ap- 

 pearance resembles the stem ; and when taken together they 

 have been, not unaptly, compared to two cones united by their 

 bases. Both take their origin from the same vital points, yet 

 under the influence of the vital power they seem to be endowed 

 with opposite propensities, — one growing upward, seeking light 

 and air, the other with an equal impulse forcing its way down- 

 ward, and burying itself in the earth. We may consider the 

 plant as endowed with opposite polarities ; one pole uniformly 

 taking the direction of gravity, the other as uniformly the op- 

 posite direction. The surface of the earth may, in general, be 

 considered the equator of this living magnet, and the zenith 

 and nadir its poles. 



Although we speak of Root and Stem being joined at a point 

 called the neck, still there is no line of demarkation drawn by 

 nature by which we may determine the precise point where the 

 stem ends and the root begins. The fibers extend from one to 

 the other, and the union is made by a gradual conversion of the 

 one into the other. The seat of vitality has been supposed to 

 be in the neck, but numerous examples will readily occur to the 

 student disproving such an hypothesis. The neck in many plants 

 may be removed, and the roots and stems will still survive by 

 proper attention ; proving not only that the neck is not the seat 

 of vitality, but that there is no such single point which if de- 

 stroyed, the plant necessarily perishes. 



66» The principal differences between the root and the stem 

 are, — 1st, the root is destitute of pith, and 2d, the true spiral ves- 

 sels are not developed in it, hence no medullary sheath : 3d, 

 there are generally no regular buds formed on the roots ; yet 

 they are capable of putting them forth under favorable circum- 

 stances, as may be seen in the shoots that spring from the roots 

 of the Peach, Plumb, Cherry, and Poplar : 4th, Stomates are not 

 found in the bark of the roots. 



In other respects the root does not differ from the stem, and 

 the differences above noticed are in a great degree owing to the 

 situation of the root. The moist, resisting medium in which it 

 is placed, produces the variation, rather than any real difference 

 of organization. Stems, when exposed to different influences, 

 change their type of organization to fit themselves to the dif- 

 ferent circumstances in which they are placed. 



The most important distinction, on which our idea of the root 



To what may the stem and root be compared ? — 66. What are the differ- 

 ences between root and stem ? To what may their differences be in some 

 manner ascribed? What is thj most important distinction ? 



