ON THE EXCRETIONS. OF THE ROOTS OF PLANTS. 



75 



a piece of ground as I have selected, aided by a few judicious plantations. Care 

 should be taken also to make the water at the lowest level, as it would produce 

 an unreal and consequently disagreeable effect to see a sheet of water at a certain 

 level, and a dry hollow still lower, unless some' great natural barrier was present 

 to account for it ; which is only likely to occur in abrupt mountainous scenery. 



Approaching nearer the residence the plantation ought gradually to assume a 

 more regular character, and lower ornamental and evergreen shrubs should be 

 introduced in those — round the lawns large showy flowers should be planted 

 irregularly — the front of the shrubs, whose foliage would form a rich dark back- 

 ground to the bright colours, and prevent their forming gaudy and inharmonious 

 patches. In the front I would have no nearer approach to flower gardening than 

 this. At the back I would, at the distance of forty or fifty yards, have a sunk 

 fence, surmounted by a low stone wall, about two feet high, upon which I would 

 place large simple jars or vases, at long distances, which should contain trailing 

 plants, to prevent a too neat and architectural effect. Between this fence and 

 the house should be the flower-garden, arranged in any bold square plan the fancy 

 may suggest, but all must here be angular, and no attempt at landscape or 

 serpentine must be made. 



( To be continued.) 



ON THE EXCRETIONS OF THE ROOTS OF PLANTS. 



Perhaps there is no subject more interesting or more valuable to the agricul- 

 turist or horticulturist than this, inasmuch as upon a knowledge of this fact depends 

 the judicious arrangement of a rotation of crops : and perhaps few subjects are 

 really less understood. It is well known to agriculturists, that they cannot 

 grow wheat or any other vegetable successively on the same ground, notwith- 

 standing the soil may be annually well manured ; it therefore cannot be con- 

 sidered to arise from an impoverished state of the soil. But the cause is 

 now known to originate in a peculiar excretion of the root, which varies in 

 different vegetables. This peculiar excretion was first discovered by Brugmans, 

 who placed a plant of Viola arvensis in a clean transparent vessel. On examina- 

 tion he found that it had during the night dropped very small particles at the 

 extremity of the roots. Since that time he has often found small grumous 

 matter at the extremities of the roots of many species of Euphorbia, and 

 Cichorium, as also of Scabiosa arvensis, Inula: helenium, &c. ; and as these grumous 

 particles appeared to him not to be the result of accident, he considered them to 

 be excretions of the root. 



In 1805, Decandolle called the attention of botanists to this subject, and 

 frequently solicited many chemists to investigate the properties of this matter. 

 In 1831, Mr. Macaire, a distinguished chemist at Geneva, and friend of Ocean- 

 ia 2 



