1838] 



FARMERS' REGISTER. 



639 



The disposition of trees may, however, be 

 changed gradually in many inptances ; and tlie 

 operation ol' a new climate in this way be made 

 supportable. The myrtle, a native of the south 

 of Europe, inevitably dies if exposed in the early 

 state of its growth to the frosts of our winter; but 

 if kept in a green-house dnringihe cold season (or 

 successive years, and gradually exposed to low 

 temperatures, it will, in an aiivanccd stage of 

 growth, resist even a very severe cold. And in 

 the south and west of England the myrtle flou- 

 rishes, produces blossoms and seeds, in conse- 

 quence of this process, as an unprotected standard 

 tree ; and the layers from such trees are much 

 more hardy than the layers from myrtles reared 

 within doors. 



The arbutus, probably originally from similar 

 cultivation, has become the principal ornament of 

 the lakes of the south of Ireland. It thrives even 

 in bleak mountain situations; and there can be 

 little doubt but that the offspring of this tree, 

 inured to a temperate climate, might be easily 

 spread in Britain. 



The same principles that apply to the effects of 

 heat and cold will likewise apfily to the influence 

 of moisture and dryness. The layers of a tree 

 habituated to a moist soil will die in a dry one; 

 even though such a soil is more favorable to the 

 general growth of the species. And, as was 

 already stated, trees that have been raised in the 

 centre of woods are sooner or later destroyed, if 

 exposed in their adult state to blasts, in conse- 

 quence of the felling of the surrounding timber. 



Trees, in all cases in which they are exposed in 

 high and open situations to the sun, the winds, 

 and the rain, as I just now noticed, become low 

 and robust, exhibiting curved limbs, but never 

 straight and graceful trunks. Shrubs and trees, 

 on the contrary, which are too much sheltered, 

 too much secluded from the sun and wind, extend 

 exceedingly in height, but present at the same 

 time slender and feeble branches; their leaves are 

 pale and sickly, and in extreme cases they do not 

 bear fruit. The exclusion of light alone is suffi- 

 cient to produce this species of disease, as would 

 appear from the experiments of Bonnet. This 

 ingenious physiologist sowed three seeds of the 

 pea in the same kind of soil: one he suffered to 

 remain exposed to the free air; the other he in- 

 closed in a tube of glass; and the third in a tube 

 of wood. The pea in the tube of glass sprouted, 

 and grew in a manner scarcely at all different 

 from that under usual circumstances; but the 

 plant in the tube of wood, deprived of light, be- 

 came white and slender, and grew to a much 

 greater height. 



The plants growing in a soil incapable of sup- 

 plying them with sufficient manure, or dead or- 

 ganized matter, are very generally low, having 

 brown or dark green leaves; and their woody 

 fibre abounds in earth.* Those vegetating in 



* This is very strikingly illustrated in many of the 

 plants which grow out of the soft free -stone rock of 

 Malta: their growth is stunted; their roots large, 

 branches and leaves small; and their leaves as well as 

 branches abound in lime. From what I have witness- 

 ed in that island, I am disposed to believe that plants 

 are instrumental in effecting cavities in calcareous 

 rocks, and that many perforations which have been 

 referred to the operation of boring salt-water mollusca 

 are owing to vegetable growth and decay.— J. D. 



peaty soils, or in lands too copiously supplied 

 with animal or vegetable matter, ra|)idly expand, 

 [iroduce \nr^e bright green leaves, abound in sap, 

 and sxenerally blofsom prematurely. 



Where a land is too rich f()r corn, it is not an 

 uncommon practice to out down the first stalks, as 

 by these means iis exuberance is corrected, and it 

 is less likely to fall before the grain is ripe; excess 

 of poverty, or of richness, is almost equally ffital 

 to the hopes of the farmer; and the true constitu- 

 tion of the soil lor the best crop is that in which 

 the earthy materials, the moisture and manure, 

 are properly associated; and in which the decom- 

 posable vegetable or animal matter does not ex- 

 ceed one-fourth of the weight of the earthy con- 

 stituents. 



The canker, or erosion of the bark and wood, 

 is a disease produced often in trees by a poverty 

 of soil; and it is invariably connected with old 

 age. The cause seems to be an excess of alka- 

 line and earthy matter in the descending sap. I 

 have often found carbonate of lime on the edges 

 of the canker in apple trees; and ulmin, which 

 contains fixed alkali, is abundant in the canker of 

 the elm. The old age of a tree, in this respect, is 

 faintly analogous to the old age of animals, in 

 which the secretions of solid bony matter are al- 

 ways in excess, and the tendency to ossification 

 great. 



The common modes of attempting to cure the 

 canker are by cutting the edges of the bark, bind- 

 ing new bark upon it, or laying on a plaster of 

 earth; but these methods, though they have been 

 much extolled, probably do very little in producing 

 a regeneration of the part. Perhaps the applica- 

 tion of a weak acid to the canker might be ofusej 

 or where the tree is of great value, it may be wa- 

 tered occasionally with a very diluted acid. The 

 alkaline and earthy nature of the morbid secretion 

 warrants the trial; but circumstances that cannot 

 be foreseen may occur to interfere with the suc- 

 cess of the experiment. 



Besides the diseases having their source in the 

 constitution of the plant, or in the unfavorable 

 operauon of external elements, there are many 

 others perhaps more injurious, depending upon 

 the operations and powers of other living beings; 

 and such are the most difficult to cure, and the 

 most destructive to the labors of the husbandman. 



Parasitical plants of different species, which at- 

 tach themselves to trees and shrubs, feed on their 

 juices, destroy their health, and finally their life, 

 abound in all climates; and are, perhaps, the most 

 formidable of the enemies of the superior and cul- 

 tivated vegetable species. 



The mildew, which has often occasioned great 

 havoc in our wheat crops, and which was parti- 

 cularly destructive in 1804, is a species of fungus, 

 so small as to require glasses to render its form 

 distinct, and rapidly propagated by its seeds. 



This has been shown by various botanists; and 

 the subject has received a full illustration from the 

 researches of the late ever to be lamented Sir 

 Joseph Banks. 



The fungus rapidly spreads from stalk to stalk, 

 fixes itself in the cells connected with the com- 

 mon tubes, and carries away and consumes that 

 nourishment which should have been appropriated 

 to the grain. 



Various remedies have been proposed for this 

 disease. The JRev. Dr. Cartvvright states that he 



