238 



THE FARMERS' REGISTER. 



utmost size under a concurrence of wet eeasons 

 and high manuring, and their least under the 

 opposite contingency. There appear to be good 

 grounds (or believing, too, that wherever circum- 

 stances lavor the grovvih of one of these classes 

 of root?, that of the other is correspondingly re- 

 tarded. 



Wiih a view to ascertain whether or not this 

 disposition of the roots of the corn plant were 

 affected by the texture of the soil and subsoil, 

 several plants were next examined, growing in a 

 close and heavy soil, based on a stiff subsoil, con- 

 sisting principally of clay with some sand. But 

 here, also, the same law was found operating in 

 giving a downward tendency to the main roots. 

 They were observed, however, to be more nume- 

 rous, and to reach an average depth of only two 

 feet, their progress downwards, being no doubt 

 obstructed by the resisting quality of the subsoil. 

 The horizontal roots, though of smaller diameter 

 than the perpendicular, were so much more de- 

 veloped than in the former case, especially when 

 favored by a moist and niellow soil, as to traverse 

 and occupy the entire intervals (a space of five 

 feet) between the rows. 



The results of the above examinations certain- 

 ly go to show, then, that the opinion of the Cul- 

 tivator is not in strict harmony with facts, at least 

 in this locality : that, in short, the principal roots 

 of the plant, underconsideration,so far from pene- 

 trating only eight or nine inches below the sur- 

 face, actually reach a depth of several feet ; while 

 the horizontal, which that journal seems to regard 

 as the principal roots, are, in point of fact, smaller 

 (though often longer) ones given off from the 

 former. It has been seen, moreover, that the re- 

 lative dimensions of these two sets or classes of 

 roots are not always the same; their respective 

 developements depending, as they do, on the con- 

 trolling influence of the several ever varying 

 causes enumerated. 



We cannot reflect on the foregoing facts with- 

 out at once perceiving, and, in some degree, ap- 

 preciating their practical bearing. Nor can any 

 one, acquainted with the habits of this plant, fail 

 to discover the wise adaptation of means to the 

 end displayed in the number and position of its 

 larger roots. One happy and very obvious effect 

 of this arrangement is, a degree of exemption 

 from the efTecls of drought, which could not be 

 enjoyed under any other. Hence it is that corn, 

 although so susceptible of injury from this cause, 

 does not suffer more from it. For it cannot be 

 ■questioned that, with its present physiological 

 ■constitution unchanged, the harm it would sustain 

 would be much greater were its roots horizontally 

 placed, and of course near the surface. Indeed, 

 this fancied position of its roots can never sufB- 

 ciently account for the readiness with which this 

 plant suffers from drought. This phenomenon is 

 clearly referable to nothing else than the organi- 

 zation of the entire plant itself. The most obvi- 

 ous of its features — its size, the well-known po- 

 rous structure of its stock and leaves — its rapid 

 foliar transpiration, &c., sufficiently indicate the 

 need of a quantity of sap both absolutely and re- 

 latively large. Now, as water is essential to the 

 formation of sap, and constitutes such a large pro- 

 portion of it, it would seem evident that this plant, 

 which contains so much sap, must require a cor- 

 responding quantity of water, and must suffer 



sooner for the want of it, than if its relative portion 

 of sap were much less. 



Indulge me here, JVlr. Editor, with a remark or 

 two on this point relatively to the cotton plant. 

 Its capability of resisting drought has been attri- 

 buted, in a published communication, to its tap- 

 roof. This, it is supposed, by penetrating to a 

 great depth, furnishes a supply of moisture suffi- 

 cient to enable it to withstand a drought, by which 

 corn would be seriously injured if not destroyed. 

 In order to determine the truth in this matter, I 

 have pulled up and examined a great many planta 

 after the loth or 20ih of July ; but have found a 

 large proportion of them with no tap-root at all : 

 while in others this root had either assumed a 

 lateral direction, or had become so diminutive in 

 size, and inferior to the lateral, as to be evidently 

 incapable of the eflect above ascribed to it. Yet 

 these plants were as little affected by drought and 

 as productive as the tap-rooted. Now if the lat- 

 ter resist drought by virtue of their tap-roots, by 

 virtue of what do the non-tap-rooted plants resist 

 hi Were it this root alone that conlerred immu- 

 nity from the effects' of a dry season, one might 

 expect during such a time easily to distingnish be- 

 tween them while growing ; but this, it is believed, 

 cannot be done ; and it is more than probable that 

 the relation of this plant to the season is as little 

 controlled by its tap-root as that of the corn plant 

 is by its horizontal roots. The former, whatever 

 may be its degree of succulency, becomes gradu- 

 ally more and more woody, until at maturity, it 

 acquires the closeness of texture and hardness of 

 many shrubs. While, on the other hand, the 

 stalk of the latter is more or less occupied by a 

 pith so filled with sap that it may be wrung from 

 it almost as water from a saturated sponge. Were 

 equal portions, by bulk, of cotton and corn-stalk, 

 at the same period of their growth, deprived of 

 their sap, the quantity from the former would 

 doubtless be much less than that from the latter: 

 lor the very obvious reason, that the dense and 

 compact structure of the one is incompatible with 

 that capacity for sap existing in the very licht and 

 porous pith of the other. Hence it would seem 

 safe to conclude, that cotton, containing, as it does, 

 less sap, requires less moisture than corn; and 

 is, of course, better able to sustain itself during 

 drought, even supposing the relative activity of 

 the leaves to be the same in both plants. This opi- 

 nion is corroborated by the effects of the great 

 drought of 1839 on some of our forest trees situ- 

 ated in certain high and thirsty localities. The 

 oaks, BO far as I observed, exhibited no evident 

 symptoms of injury, while the p^mes growing 

 among them lost, in some instances, a moiety of 

 their leaves. Here then the case of cotton and 

 corn is reversed ; the tap-rooted plant suffering 

 least in one case, and most in the other. This, it 

 is conceived, can only be explained by reference to 

 a difference of organization ; the result of which 

 was, that the pine, though fortified by an im- 

 mense tap-root, became the earlier and greater 

 sufferer. »#.*»»*» 



L. Reeve Sams, M. D. 



