CHAP. CXIIl.

CONl'FERiE. ABIE'TINJE.

2107

taken by its branches in every stage of its growth; and the branches ofAf'bies canadensis are equally remarkable for their slenderness, and droopingcharacter.

The roots of the dbietinae differ from those of almost all other trees, in notdescending perpendicularly; but, both in young and old trees, spreadingalong the surface of the ground; and, very generally, after the trees haveattained some age, swelling and appearing above it. They are numerous, andof less thickness in proportion to that of the trunk, than in the case of anyother trees, except the palms; but, being near the surface, and often partiallyabove it, they are of a more tough and woody nature, and are, consequently,better able to resist the action of the wind on the head of the tree, than inthe case of trees the roots of which run deep under ground, and which areconsequently much less tough and woody. The vitality of the roots of somespecies is most extraordinary; stumps of the silver fir (Picea pectinata) havingbeen found in a growing state, but without leaves, after the trunk had beencut down for upwards of 40 years. The roots of none of the species throwup suckers; nor, when the stems are cut down, do shoots spring from thecollar. In some species, as in P. Parda and its varieties, numerous abortiveshoots, or tufts of leaves, are produced from the old trunk; and some of theAsiatic and Mexican species also indicate this tendency, though in a muchslighter degree.

The trunk, in all the species, grows erect and straight; in some, as in thePicea pectinata of Europe, it attains the height of 130 ft. or upwards, with adiameter of from 4 ft. to 8 ft.; and, in the Picea grandis of America, it issaid to attain the height of 200 ft. The stem is almost always beautifullyand regularly tapered, and without those large protuberances common intrees which have their branches of equal durability to the trunk itself, and oflike capacity for attaining as large a size. Where the Abietinae have beengrown close together, the trunks are almost always straight, and frequentlywithout a single branch to the height of 80ft. or 100ft.; the side branches,in such cases, prematurely decaying, from the absence of light and air. Trunksof this kind are common in the spruce fir plantations of Sweden and Norway;and they constitute the fir poles of commerce, so much used throughoutEurope as masts for small craft, and as supports for scaffolding. Trunks ofthe same character are also found in the pine forests of the north of Europeand of North America: and from them are made the masts of the largestAmerican ships; and the beams, rafters, joists, and boards, used in civilarchitecture, and particularly in the construction of houses in the temperateclimates of both hemispheres.

The branches, in the greater number of the species, are vertieillate, hori-zontal in their direction, uniform in their size and shape, and, with thesmaller shoots, especially in old trees, generally pendent. In all, the mainshoot of the branch is slender, and never attains a great thickness. Insome genera (as in Picea) the branches are frondose, and quite flat; havinga slender main shoot, regularly furnished with smaller side shoots; which areagain subdivided into numerous twigs, or spray; and the surface of thewhole is flat, like that of the leaf of a fern. In A'bies and Larix, the sidebranchlets, which proceed from the main shoot of the branch, are for the mostpart pendent. In Cedrus, the branches are more woody than in the case of anyother genus; and in Pinus least frond-like. As the tree advances in growth,the branches die off, beginning from below; more especially where severaltrees have been associated together. There are, however, exceptions in thecase of single trees in favourable situations, when the branches assume awoody and permanent character; and this is very frequently exemplified insingle trees of the cedar, the silver fir, and the Scotch pine, which havehad their trunks broken over at a certain stage of their growth. Indeed,pinching out the leading shoot of any species for two or three years in suc-cession, when the tree is young, will generally cause it to produce, insteadof a single trunk, a number of trunk-like branches, which form a bushy tree,