326 Growth of Trees 



themselves, except in rotten wood ; but, as the first holes made 

 by the larger species become smaller every year, they may 

 accommodate themselves in them, or in any other cavity of the 

 tree. They are, however, well adapted, from their activity and 

 prying habits, to devour the smallest wood-eating insects, which 

 escape the notice or taste of the larger birds. 



Upon the whole, it may be rationally concluded that the 

 woodpeckers perform a necessary and useful part in the scale 

 of animated nature, and contribute greatly in maintaining that 

 balance among the insect tribes which are destined to live on 

 trees, by checking excessive reproduction, and, consequently, 

 repressing excessive depredation. 



I therefore earnestly recommend the woodpeckers to the 

 protection of the gardener, the forester, and to the game- 

 keeper, who may be well assured that those birds, instead of 

 doing any kind of damage, actually do a great deal of good. 



Jj)ril 20. 1838. 



Art. III. Some Account of the Grototh of the Trees in the Park at 

 Botvood, the Seat of the Marquess of Lansdowne. By J. Spencer, 

 Gardener there. 



Having had an opportunity of examining and comparing the 

 growth of the trees in the grounds here, I have sent it to you, 

 as, perhaps, it may serve to corroborate some facts before stated, 

 or refute others respecting which doubts existed. I by no 

 means think there is interest enough in it for publication : I 

 merely send it, as a reference of the respective rates of growth 

 of the trees specified below. 



The soil in which the different trees are mostly planted is of 

 a thin, sterile, sandy nature, on a substratum of (^[uicksand, and 

 a species of peat ; the water rising all over the grounds to 

 within a few feet of the surface ; a circumstance essential to the 

 growth of the ^bietinae. The principal part, if not all, of the 

 trees specified below, where raised here from seed sown sub- 

 sequently to the year 1770 (say 1770 to 1785), and planted in 

 groups, as they now appear. The rate of growth, as regards 

 quantity of timber, is, Pinus Pinaster, ^ bies excelsa. Pin us 

 (Strobus, Pin us sylvestris, ^^bies nigra, Picea pectin ata, and ^^bies 

 alba; but these are inferior in that respect to Cedrus Libani, 

 which exceeds them in bulk of timber in a given number of 

 years. 



I now give you the dimensions of the following species, 

 being all planted under similar circumstances, and at the same 

 time : — 



