PI. IV. 



PRUXK\G Ax\D TIIINXING. 



217 



deposit of wood and bark takes place on their outside, 

 -while their inside is sloughing, or rotting off, and these 

 detached strips gradually and annually progress out- 

 wards from where the centre of the tree was. 



When old pollards are cut over, they throw out 

 new branches most vigorously, which militates against 

 the theory that all new branches are from original 

 latent buds, and from the central pith ; since old pol- 

 lards may be found not only destitute of central pith, 

 but the oldest part of whose stem-wood is possibly not 

 ten years of age. So that the casuist might raise the 

 question whether these, our supposed oldest trees, are 

 not actually among our youngest ; as the identity of 

 the sliip Argo was disputed when, from constant 

 gradual repair in the temple where it was preserved, 

 every part of the old ship had disappeared and had 

 been replaced. Nay, since whilst a pollard is becom- 

 ing hollow the internal decay surpasses the external 

 growth, it may be said to become younger by age ; 

 and when decay and growth balance each other, that 

 age, or the addition of years, makes it no older. 



The great secret of large timber is, centuries of 

 non -cutting down, good soil, room, and sheltered 

 situation. These conditions rarely come together in 

 cultivated countries, though they do sometimes in our 

 old family places. The free growth and the enormous 

 measurements of trees in the forests of uncultivated 

 countries are more frequently to be attributed to the 

 concurrence of the favourable conditions above s^^ated, 



