346 Prof. De CandoUe on the Longevity of Trees, 



I give these approximations to travellers, as indications, and to 

 induce them to verify the data on which they are founded. 



As to endogenous trees branching, and without regular rings, 

 we are not aware of any plan for establishing their age, and the 

 problem ought to be laid before observers without limitation. 

 We know that some of the trees belonging to this class reach an 

 extreme longevity, such as the famous dragon-tree (Dractiena 

 draco) of the garden of Franchi, at Orotava, island of Teneriffe, 

 which was a celebrated tree in 1402, at the discovery of the 

 island, and at that time an object of veneration among the peo- 

 ple. Mr Berthelot *, who has published an accurate descrip- 

 tion of it, says, that on comparing the young dragon-trees which 

 are in the vicinity of this gigantic tree, the calculations which he 

 has made as to the age of the last have more than once asto- 

 nished his imagination. In 1796, according to Mr Ledru, it 

 was 20 metres in height, 13 in circumference at the middle, and 

 24 at the base ; since that time, the hurricane of 21st July 1819 

 has destroyed a great portion of the top of it. 



I am induced to think that, among perennial plants and small 

 shrubs, there are some which are older than we are accustomed 

 to beheve, but on this point there have been no inquiries. I 

 shall here mention some incomplete facts, which may encourage 

 observers to direct their attention to the .duration of these hum- 

 ble vegetables. In vegetable organography, I have taken notice 

 of the singular willow, called herbaceous, which, when it grows 

 on the mossy ground of the Alps, in places below the declivities, 

 the soil of which moves away slowly, is gradually covered, and 

 stretches itself out to an extent absolutely necessary to reach the 

 surface, in such a manner that it presents the appearance of a 

 green turf many yards in extent, and is in reality the top of a 

 subterraneous tree. I have attempted to uproot this singular 

 kind of tree, but never could reach its inferior extremity, though 

 the length which I dug out, compared with the extreme slow- 

 ness of its spreading, indicated a very advanced age. It would 

 be curious to reach the lower end of this tree, which, owing to 

 its subterranean existence, escapes the inclemencies of the atmo- 

 sphere. 



I have seen Eryngiums and Echinophoras in the downs of the 

 , , * Mem. Cur. Nat. vol. xiii. p. 781. 



