1885.J HISTORICAL SOTICK OF CELEBIiATKU TREES. 433 



baobab and the lime, like most of tlie Conifenp, afford wood of a 

 soft quality. 



In taking measures of different trees, much error arises from one 

 taking the girth near tlie root, another 3, 4, or 5 feet from tlie 

 ground, and a third at the springing of the brandies. Tlie truth is, 

 no particular height ought to be adopted, and a different mode of 

 measurement ought to be followed if we intend future naturalists to 

 draw deductions from our ol)servations. Close to the root the trunk 

 swells out considerably, and it does the same wliere tlio branches 

 originate ; between these points the outline of the trunk forms a 

 curve, and the proper place fur measuring its circumference is where 

 that circumference is smallest. This ought to be ap[)lied to all 

 trees except the pine. 



The subject is of great interest, not only in an agricultural and 

 commercial point of view, but in a pliysiological, as it lias led 

 De Candolle to propound the theory that trees in their native soil, 

 and not subject to external injuries, would survive as long as the 

 world itself. 



Before concluding, I cannot refrain from drawing your attention 

 to the Dracccnc draco, or dragon tree. I mentioned that the age of 

 certain, but not of all plants, could be ascertained by means of the 

 annual layers, and that the palms showed no layers. Xow, althou<di 

 the Dracccnc is not a palm, it belongs equally with them to the 

 great class of monocotyledonous plants, in which the deposit of 

 woody matter is made in quite a different way from what wq 

 observe in the oaks, limes, cypresses, and others we have enumerated, 

 all of which belong to the dicotyledonous tribe of vegetables. Now 

 among those which have no annual rings the Draccene stands pre- 

 eminent, and of these the famous dragon tree of the city of Orotava, 

 in Teneriffe, furnishes a case of longevity perhaps transcending that 

 of the oldest baobabs, or of the Mexican cypresses. This tree has 

 been visited by many competent observers, and among others by 

 that prince of scientific travellers, the veteran Humboldt, who has 

 given a good figure of it as it appeared about 70 years ago, from a 

 drawing made by M. Ozonne in 1776. A later and much fuller 

 account was published in 1827 by M. Berthelot, and a fine figure 

 of the mutilated trunk, as it appeared after the terrible storm of the 

 21st July 1819, forms one of the most striking pictorial illustrations 

 of Webb and Berthelot's Histoirc Ncdurcllc dcs lies Canaries. 



The trunk is by no means equal in size to some of the dicotyle- 

 donous trees I have noticed. It is only 50 feet in girth at the 

 base, and not more than 60 or 70 in height. But, at the discovery 

 of Teneriffe in 1402, over 4^ centuries ago, this dragon tree was 

 nearly as large as at the present time, and had been immemorially 



