2390 ARBORETUM AND FRUTICETUJl. PART III. 



it decaj's at the heart, after arriving at 40 years of age. In situations where 

 water stands for a length of time about the roots, it becomes covered with 

 lichens; but in all rocky situations, and particularly those which are composed 

 of mica-slate containing crystals of garnets, among the fissures and fragments 

 of which they can push down their roots, larches thrive to admiration. The 

 geognostic character of tlie country from Dunkeld to Blair is primitive. At 

 Blair is gneiss, at Dunkeld clay-slate, and the intermediate space is occupied 

 by mica-slate. They lie conformably to one another. 



" The Advantages resulling from planting Mountain Ground appear, at first 

 sight, in the greater number of trees that may be supported on the acclivity 

 of a mountain, than on a surface equal to its base. Trees derive nourishment 

 from the soil immediately around the place in which they are fixed; and, as 

 the superficies of that soil must, of course, be greater on an acclivity than on 

 the base, a greater number of trees will be there supported. Practically 

 speaking, 100 trees at 6 ft. apart can be planted on the hypotenuse of a 

 right-angled triangle, whereas the base would only permit 80 at the same 

 distance. Another and a great advantage derived from planting mountain 

 ground is, that, on an acclivity, the trees expose a greater surface to the 

 influence of the sun, air, and rain, than they can do on a level surface. The 

 outside trees in a forest are always the strongest. On an acclivity they all 

 possess the advantages of outside trees, and at the same time most of the 

 shelter enjo3-ed by those in the interior." 



Kiimber of Plants annually 2^lcinted. " From the great scarcity of arch 

 plants at the commencement of the larch plantations at Athol, it was not 

 possible to extend their cultivation beyond a very limited number or space in 

 any one year. They were at first planted very little thicker on the ground, 

 among other trees, than they would liave been, had they been thinned out to 

 stand for naval purposes. Generally, in mixed plantations, they were put 

 in from 700 to 1000 plants per acre. In the first attempts at planting them 

 entirely by themselves, they were increased only to loOO plants per acre, from 

 the want of plants. The keeping of the plants in the nursery grounds till 

 they were 3 and 4 years transplanted from the seed-bed, tended greatly to 

 decrease the disposable quantity of plants from such sources. Finding 1500 

 plants rather too few among broom and furze, they were increased to 1800 

 per acre. Even after one-year-old seedlings were planted, which practice 

 immediately threw an immense number of plants into the market, they were 

 only 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 thin 

 planting, and up to the region of broom and furze, that number may have 

 enough to do to contend with them ; for, however these shrubs might have 

 been subdued for a time, and, in many places, com[)letcly eradicated, yet, in 

 more favourable situations, they would spring up again, were there not a 

 sufficient number of trees to overtop and keep them down, by the exclusion 

 of the pure atmospheric air. It must be observed, however, that were 3000 

 plants planted per acre, that would only bring the trees about half a foot 

 closer to each other ; whereas the lower branches of the 2000, having plenty 

 of air, will meet one another when the plants are only eight years old from 

 the 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 per 

 acre, the duke maintains, are not too few, when it is considered, in the first 

 place, that this open planting delays greatly the period of thinning, and, of 

 course, curtails expense, which is an object of consideration in large under- 

 takings. In tiie next place, it is well known, that the lower branches of the 

 larch assist more than any of the others to strengthen the roots, and increase 

 the thickness of the base of the trunk of the tree. Strcngtii of roots and 

 a good girt give great stability to trees exposed to the lury of the elements in 

 a mountainous country. The tops of the larch vibrate in the blast like the 

 points of fishing-rods. By the time they are thinned, they will individually 

 be able to withstand great blasts of wind with impunity, jiesides, the lower 



