402 



THE GEOLOGIST. 



There appear to be, as far as we are aware, no published sections 

 of their structure, nor any particularly valuable descriptions for the 

 geologist. Some monographs do exist of somewhat ancient date, 

 namely, Crantz, ' De Duabus Draconis Arboribus Botanicorura,' 4to, 

 Vienna, 1768 ; Berens, ' De Dracone Arbore Clusii,' 4to, Gottingen, 

 1770; Yandelli, 'De Arbore Draconis sen Dracaena,' 8vo, Olisipoiie, 

 1768 ; and Thunberg, ' Dissertatio de Dracaena,' 4to, Upsala, 1808. 

 These are all the special works which have come under our direct 

 notice. Various accounts, however, are scattered through various 

 books of travel and of expeditions; and especially any one who wishes 

 to work out the subject will find accounts and admirable photographs 

 of the great dragon-tree of Orotnva, and many others, in Professor C. 

 Piazzi Smyth's 'TenerifFe.' This Orotava-tree is reputed to be 

 6000 years of age. 



" Poor old tree, wbose trunk was hollow when Alonzo del Lugo and liis 

 conquistadores in 1493 established the Spanish authority here, and turned 

 the bark into a chapel for holy mass after it had served Druidical pur- 

 poses amongst the Guanohe tribes for ages. How frail is it now ! A storm 

 wrenched off an arm ; and more recently certain Goths hacked an immense 

 piece out of the tliin wall of hollow trunk for the Museum of Botany at 

 Eew. . . . Sixty feet high above the ground at its southern fork ; forty- 

 eight feet and a half in circumference at that level, 35-6 at 6 feet above, 

 and 23"8 at 14*5 feet above, or the place where the branches spring out 

 from the rapidly narrowing conical trunk — -this Dracaena cannot compare 

 with the real monarchs of the forest for size. And we must remember that 

 it is no proper tree with woody substance ; it is merely a vegetable ; an aspa- 

 ragus stalk, with a remarkable power of vitality and an equally eminent 

 slowness of growth : it is this last, indeed, not its size, which has gained 

 it the credit of being the oldest tree in the world. Let us take note of 

 tke chief characteristics. First, the immense uprearing of long, naked, 

 root-like branches, and the pyramidal outline of the trunk. The leafage 

 makes no very sensible appearance ; there is the typical tuft at the end of 

 each branch, or rather stem ; but the miniature palm-trees have been grow- 

 ing for ages without bifurcation, extending only in length, nothing in 

 breadth. At the point of junction of two or more a thickening of the lower 

 branch begins, and occasionally may be seen one or two withered radicles 

 hanging loose ; for they have failed to enter the bark, and work their way 

 down to the ground. So many of them however have done this, tha.t 

 while the simple stems are smooth or marked only by shallow, transverse 

 indentations of footstalks of past leaves, the compound stems are deeply 

 corrugated longitudinally, and the trunk more markedly still, v/ith an evi- 

 dent tendency in every wrinkle to divide continually as it descends. When 

 once a stem has branched its life seems to have departed, being replaced 

 by the lives of the several young trees of its kind left growing on its sum- 

 mit, and who^e roots, entering the bark, and encasing the stem on ever}^ 

 side, conceal its slowly withering corpse from the light of day. Ages pass 

 by ; the young trees after flourishing die in their turn, each producing 

 two or more new ones mounted on their summits ; . . . the inosculating 

 roots, which had decorously concealed the death of their parent stem. 



