196 De Candolle's Essay [April, 



VIII. — European Science. 



On the Longevity of Plants, and the Means of Ascertaining their Age. 

 [Translated for the J. A. S. from the Original of Professor de Candolle, at Geneva.] 

 A tree may be considered in two points of view, either as an assemblage of as 

 many individuals linked together as there are buds developed on its surface ; or as 

 a single being, analogous to what is called an individual when speaking of an 

 animal. According to the first, which is probably the most rational view, it 

 cannot be astonishing that, while new buds are incessantly being added to the old, 

 there should be no necessary term to the existence of the aggregate body. By 

 the second, which is the most common, it must be allowed that, as in the greatest 

 number of trees a fresh layer of wood, and in general new organs, are formed every 

 year, there cannot exist in the vegetable world that hardening or that obstruction 

 of the old and permanent organs which produces death from old age properly so 

 called, and that consequently trees should never die but from accidental causes. 

 By either of these hypotheses it is equally shewn that trees do not die of old age 

 in the real sense of the phrase ; that there is no definitive term to their existence ; 

 and that consequently some may be found that have attained an extraordinary age. 

 But it is not sufficient to advance such an opinion ; we must endeavour to prove 

 its truth. Already two remarkable examples have been quoted ; that of the Baobab) 

 which Adanson by ingenious and plausible calculations, has proved to be 5150 

 years old, and that of the Taxodium (Cupressus disticha, Lin.J which from analogous 

 reasoning may be considered still older. (See the notice on these trees by Mr. 

 Alph. de Candolle in the Bibl. Univ. April, 1831.) Other, though less remark- 

 able cases, seem to confirm the idea that there still exists in the world trees of 

 prodigious antiquity, that have witnessed perhaps even its last physical revolutions. 

 It is easy to imagine that many errors may creep into calculations of this sort ; 

 and that they can only be depended on as correct, when multiplied cases of 

 vegetable longevity shall be discovered to confirm the fact. I have long 

 occupied myself with this subject, as the publication of the Principles of Botany, 

 inserted (in the year 1805,) in the first volume of the Flore Francaise, will prove ; but 

 the life of man is too short for such researches : opportunities are rare ; and exam- 

 ples should above all be sought for in those countries which are not subject either 

 to frost or to the destructive hand of man. The methods also of proving the 

 age of old trees is not perhaps sufficiently known to travellers, or to those who 

 interest themselves in these kinds of inquiries, and I am therefore induced to 

 call the attention of the public to the subject by means of this pamphlet. 



A considerable degree of interest would attach to the longevity of certain trees 

 were it only from curiosity. If we consider all the other documents of antiquity as 

 precious, surely we cannot lightly pass over the knowledge that such a tree is 

 contemporary with the oldest times ; in some instances, this knowledge might 

 throw light on the history of monuments, as in like manner the history of monu- 

 ments may assist our inquiries into that of their neighbouring trees. This question 

 might even become of great utility in the history of the globe. If the certified 

 number of these veterans in the vegetable kingdom were to become very consider- 

 able ; if in the course of time their age were ascertained with greater certainty ; 

 might we not find in these facts some means of fixing the approximate date of the 

 last revolutions of the earth ? If inquiries of this kind were made in volcanic or 



