46 Yew- Threes of Great Britain and Ireland 



that for trees of 150 years the annual growth some- 

 what exceeded a line of diameter, and in those of 

 150 to 250 years that it was less than this. 



' Si pour les ifs tres ages on admet la moyenne 

 d'une ligne par an, il est probable qu'on est au- 

 dessus de la veVite, et qu'en estimant le nombre de 

 leurs annees, egal au nombre de lignes de leur 

 diametre, on les fait plus jeunes qu'ils ne sont.' 



It should be borne in mind that a line of diameter 

 means only half a line for the thickness of each 

 annual ring which represents the amount of radius, 

 or half the diameter. The trees on which De 

 Candolle's estimate was founded were evidently 

 stunted and ill-grown, making the rate of growth 

 much too low, as has been shown by the evidence 

 of well-formed trees. The calculation of the age of 

 old trees, such as those of Fortingal and Brabourne, 

 on this basis, is entirely fallacious. 



