202 De Candole's Essay [April, 



this maybe determined by alateral cut which will allow the layers to be counted. Third- 

 ly ; what law governs the increase of plane-trees for the first century of their growth ? 



8th. < — The Walnut tree is also worthy the examination of observers. Scumozzi, 

 the architect, mentions having seen at St. Nicholas in Lorraine a table made of a 

 single piece of walnut wood, which was 25 feet in width, and at which the Emperor 

 Frederick III gave a celebrated repast. No conclusion can be drawn as to the age 

 of such a walnut, seeing that the progress of the growth of these trees when old is 

 unknown ; this might however easily be verified. 



9th. — The Orange and Citron are among the number of trees cultivated in Eu- 

 rope, which grow the most slowly, and arrive at the greatest age. It is asserted 

 that the orange tree of the Convent of St. Sabine at Rome was planted by St. Do- 

 minique in 1200, and that of Fondi by St. Thomas D'Aquin in 1278. The mea- 

 sure of these trees, and the verification of these traditions, might give an approxi- 

 mation as to the annual growth of the Ayrumi of Italy. 



9th. — The Cedars which I have already mentioned, though they appear to me 

 younger than they are believed to be, are still worthy the attention of observers. 



10th. — Oaks certainly stand among the veterans of Europe, but their study 

 is still involved in mxich uncertainty, either because this tree is one of those 

 which according to the acknowledgment of all foresters are the most modified 

 by the soil, or because the wood of the Quercus peduncidata, which grows quickly and 

 runs to a great height is almost always confounded with that of the Querents sessiliflora, 

 which grows more slowly, and becomes harder and more crooked. The result of 

 this confusion, is an impossibility of making comparisons from the documents we 

 already possess. In Evelyn's Sylva, a valuable work, from which Ihave frequently 

 taken useful hints, many examples may be seen with regard to the size which oaks 

 may attain. I have reason to believe that there still exist in our own councry, oaks 

 from 1500 to 1600 years old ; but it would be desirable to have these dates verified 

 by further careful inquiries. 



11th. — The Olive is also a tree possessed with the power of growing to an astonish- 

 ing age in countries where it is not subjected to the pruning knife. Mr. de Cha- 

 teaubriand in his Itineraire, says, that the eightolives in the garden ofthe same name 

 at Jerusalem only pay one medin each to the Grand Seigneur, which would tend to prove 

 that they already existed at the time of the Turkish invasion, for those planted 

 6ince that period, pay the half of their fruit. The largest olive in Italy, men- 

 tioned by Picconi, is at Pescio : it is 25 feet in circumference. If we admit the es- 

 timate given by Moschettini that the olive grows 0.13 in. yearly, it must be 

 about 700 years old ; but this estimate taken from younger olives must be below the 

 truth. 



12th. — The Yew appears to me, of all European trees, the one which lives to the 

 greatest age. I have measured the layers of an yew, 71 years old ; Oelhafen, of one 

 of 150 years old ; and Veillard, of one of 280 years : these three measurements 

 agree in proving that the yew grows a little more than 0.10 in. a year during the 

 first 150 years, and less than a 0.1 from the age of 150 to 250. If we allow an 

 average of one-tenth a year for the oldest yews, it is probable that this exceeds 

 the reality, and that by considering the number of their years to equal the number 

 of lines in their diameter, they will be pronounced younger than they really are. 

 Now I find four measures of remarkable yews in England ; those of the ancient Abbey 

 Fontaine near Reppron, in the county of York, known in 1133, were in 1770, ac- 

 cording to Pennant, 1214 lines diameter, or more than 1200 years old. 



