2390

ARBORETUM AND FRUTICETUM.

FART III.

it decays at the heart, after arriving at 40 years of age. In situations wherewater stands for a length of time about the roots, it becomes covered withlichens; but in all rocky situations, and particularly those which are composedof mica-slate containing crystals of garnets, among the fissures and fragmentsof which they can push down their roots, larches thrive to admiration. Thegeognostic character of the country from Dunkeld to Blair is primitive. AtBlair is gneiss, at Dunkeld clay-slate, and the intermediate space is occupiedby mica-slate. They lie conformably to one another.

“ The Advantages resulting from planting Mountain Ground appear, at firstsight, in the greater number of trees that may be supported on the acclivityof a mountain, than on a surface equal to its base. Trees derive nourishmentfrom the soil immediately around the place in which they are fixed; and, asthe superficies of that soil must, of course, be greater on an acclivity than onthe base, a greater number of trees will be there supported. Practicallyspeaking, 100 trees at 6 ft. apart can be planted on the hypotenuse of aright-angled triangle, whereas the base would only permit 80 at the samedistance. Another and a great advantage derived from planting mountainground is, that, on an acclivity, the trees expose a greater surface to theinfluence of the sun, air, and rain, than they can do on a level surface. Theoutside trees in a forest are always the strongest. On an acclivity they allpossess the advantages of outside trees, and at the same time most of theshelter enjoyed by those in the interior.”

Number of Plants annually planted. “ From the great scarcity of larchplants at the commencement of the larch plantations at Athol, it was notpossible to extend their cultivation beyond a very’ limited number or space inany one year. They were at first planted very little thicker on the ground,among other trees, than they would have been, had they been thinned out tostand for naval purposes. Generally, in mixed plantations, they were putin from 700 to 1000 plants per acre. In the first attempts at planting thementirely by themselves, they were increased only to 1500 plants per acre, fromthe want of plants. The keeping of the plants in the nursery grounds tillthey were 3 and 4 years transplanted from the seed-bed, tended greatly todecrease the disposable quantity of plants from such sources. Finding 1500plants rather too few among broom and furze, they were increased to 1800per acre. Even after one-year-old seedlings were planted, which practiceimmediately threw an immense number of plants into the market, they wereonly extended to 2000 per acre, on the higher and barer parts of the moun-tain range : 2000 per acre, the duke thinks may be considered by many thinplanting, and up to the region of broom and furze, that number may haveenough to do to contend with them ; for, however these shrubs might havebeen subdued for a time, and, in many places, completely eradicated, yet, inmore favourable situations, they would spring up again, were there not asufficient number of trees to overtop and keep them down, by the exclusionof the pure atmospheric air. It must be observed, however, that were 3000plants planted per acre, that would only bring the trees about half a footcloser to each other ; whereas the lower branches of the 2000, having plentyof air, will meet one another when the plants are only eight years old fromthe seed, and they will then entirely prevent the growth of the shrubs. But,in the higher region, beyond the growth of the larger shrubs, 2000 plants peracre, the duke maintains, are not too few, when it is considered, in the firstplace, that this open planting delays greatly the period of thinning, and, ofcourse, curtails expense, which is an object of consideration in large under-takings. In the next place, it is well known, that the lower branches of thelarch assist more than any of the others to strengthen the roots, and increasethe thickness of the base of the trunk of the tree. Strength of roots anda good girt give great stability to trees exposed to the fury of the elements ina mountainous country. The tops of the larch vibrate in the blast like thepoints of fishing-rods. By the time they are thinned, they will individuallybe able to withstand great blasts of wind with impunity. Besides, the lower