Despite this constant characteristic of the Lombardy poplar, which anybody may verify for himself by examining the fine groups of them near Maidenhead and Windsor, Selby committed himself to the extraordinary statement that this tree, "planted so as to form a hedge, and being cut even at a certain height and regularly trimmed, becomes a thick and verdant hedge."[11] The asp (_Populus tremula_) is now generally spoken of by the adjectival form "aspen." Its ceaseless movement earned it the name of "quick-beam" in Anglo-Saxon, and the Lowland Scots name, "quakin' asp" (corrupted into "quakin' ash") has, so far, survived the operations of School Boards. Long may it do so! The same characteristic in this tree gave it the Gaelic name of _crithean_ (creean) or _criothach_ (creeagh), "the trembler," which may be recognised in such place-names as Creechan in Dumfriesshire and, perhaps, Crieff, in Perthshire. Although in bulk and stature one of the humbler members of the poplar family, the asp exhibits in an extreme form a peculiarity common to all the genus--namely, that of hanging the leaves vertically, instead of holding them horizontally. The leaves are glandular on both surfaces, which may be either the effect of or the reason for their assuming a position protecting both surfaces from the direct rays of the sun. To secure this position, the petiole, or foot stalk, of each leaf, being cylindrical in most of its length, is suddenly flattened midway between the leaf and the twig, as if it had been pinched while soft. This causes the leaf to hang as described, and to quiver with the slightest breath of air. The asp is a hardy mountaineer; its graceful foliage and _eau-de-Nile_ bark saves many a Highland hillside from dreariness, but it has long ceased to have the economic importance it once had. By an Act of the English Parliament (4 Henry V. c. 3), a penalty of 100 shillings was imposed upon anyone who put aspen wood to any other purpose than the making of arrows. Mrs. Hemans has woven into verse the mediæval myth which taught men to reckon this pretty tree accursed: Oh! a cause more deep, More solemn far, the rustic doth assign To the strange restlessness of those wan leaves. The cross, he deems, the blessed cross whereon The meek Redeemer bowed His head to death, Was formed of aspen wood; and since that hour Through all its race the pale tree hath sent down A thrilling consciousness, a secret awe, Making them tremulous, when not a breeze Disturbs the airy thistle-down, or shakes The light lines of the shining gossamer. Gerard, writing in the sixteenth century, says, with scant gallantry, that the asp "may also be called _tremble_ after the French name, considering it is the matter whereof women's toongs were made, which seldom cease wagging." [Illustration: LOMBARDY POPLAR IN SUMMER] [Illustration: LOMBARDY POPLAR IN WINTER]