CULTIVATION OF PLANTS. 97 



in coming up induced me to suppose that they had perished from cold and 

 wetness; but at the expiration of three weeks they made their appearance, and 

 although the ground remained open several weeks longer, no second leaf ap- 

 peared, of course no joint or second system of roots had been formed. The 

 very different formations in the roots of wheat, which this experiment has 

 disclosed, proceeded from causes appropriate and capable of being ascertained, 

 but to distinguish them with certainty, other trials must be made and conduct- 

 ed with greater accuracy than the one of which an account has been given. 



From these experiments, though inaccurate, some conclusions may perhaps 

 be drawn of practical use. All plants, which live over winter, possess an ap- 

 paratus, by which they supply themselves, in autumn, with food for their sus- 

 tenance in spring. This food consists mostly of saccharine matter which is 

 enclosed in a proper receptacle. When this receptacle is formed near the 

 surface of the earth, the fermentation of its contents is excited by frequent 

 changes of weather, the saccharine matter is decomposed, and the plant 

 perishes from the want of food, and perhaps also from a rupture of its vessels. 



All wheat, shallow sowed, must have its reservoirs of food but slightly 

 covered with soil, and of course they are full exposed. When wheat is sown, 

 early at any depth, a second and, sometimes, at least, a third system of roots 

 is formed within an inch of the surface. In these many stems originate, each 

 of which has its receptacle of nourishment at its base, and it is quite certain 

 that in most instances, the food which was contained in the seed and the ad- 

 joining knot is entirely exhausted by the suppliesof nourishment it affords the 

 upper portions of the plant. The life of early sowed wheat must then, like 

 that which is shallow sowed, depend upon the preservation of the reservoirs of 

 saccharine matter which are placed at or near the surface of the "round, and 

 of course exposed to the unfavourable action of variable weather during 

 winter. 



Wheat, which is late sowed, generates no second blade or new system of 

 roots, and of course the nourish incut I'.T spn: retained in the recep- 



tacle which adjoins the seed. If then we sow sufficiently late in autumn, and 

 place the seed deep in the soil, we shall provide every security against the 

 hazards of bad weather which the nature of the case admits of. 



In the ordinary course of husbandry, some of the wheat is necessarily de- 

 posited at considerable depth in the soil, and when this takes pla;-e sufficiently 

 late in the season, the receptacle of food will be protected by its covering of 

 earth, and a partial crop will often be reali/ed, although there may be, when 

 the spring opens, no si^ns of life on the surface of the field. In such cases as 

 the destruction of the blade, which isvm'N from the seed-roots in autumn, can 

 be of little importance, one would suppose that the surviving plants would 

 grow the more vigorously, from their being less in number, and, by tillering, 

 produce many steins with large well filled ears; such however is not the fact; 

 usually the stems are single and the heads are not larjre. To account for this, 

 it must be recollected that, after the ground has thawed in spring, the earth 

 settles and often becomes so extremely hard that doubtless many plants die, 

 in their struggle to overcome the opposing resistance, and the surprise is, that 

 any should possess vigour enough to protrude even a single stem through the 

 hard earth that covers it. 



From this view of the subject, the practice may be 'recommended, of ef- 

 fectually harrowing the field in the spring after the ground has settled, in 

 order to supply the plant with fresh air and yive a free passage to its upward 

 growth. After the harrow has been used, the roller ought to be employed to 

 reset such roots as have been displaced and diminish the evaporation of mois- 

 ture. 



In England a wheat plant was taken up, separated into eighteen parts and 

 replanted, and by successive divisions and replantations, a crop of three and 

 one-third pecks of wheat was obtained in less than eighteen month 5 ? from the 

 time the seed was sown. If the roots of wheat can be so minutely divided and 

 successfully replanted, there is little danger that the freest use of the harrow 

 can be injurious, provided the roller be also used. The fact appears to be, 

 that nothing is necessarv to the vernal growth of the plant, but the preserva- 

 tion of the apparatus which contains the saccharine matter which is its proper 



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