136 



LETTERS ON TREES. 



occupied, seemed to grow together and coalesce, com- 

 pletely filling up this chasm, and ultimately presenting 

 all the characters of wood — or at least giving to the 

 once decayed Oak the aspect of a sound and entire 

 tree. 



4. Mr Jesse, in his Gleanings in Natural History, 

 gives two instances of the like occurrence — the one in 

 an Oak, the other in an Alder ; and Professor Balfour, 

 in his Class-Book of Botany (p. 446), refers to two 

 others — the one in a species of Willow {Salix vimi- 

 nalis) near Sleaford, in Lincolnshire ; and the other in 

 a large specimen of Mountain Ash at Prestonhall, 

 near Edinburgh. Mr Jesse's account of it in the 

 Alder is so much to my present purpose that I quote 

 it entire. Some years ago, I remarked an old Alder 

 that seemed to have been decayed and hollow for a 

 great length of time, and I observed from a flourishing 

 branch in the upper part of the tree a sort of roots 

 coming down, as if in search of the earth for nourish- 

 ment. Mr Nicholson and I have frequently visited 

 it, and found that the roots crept down the hollow 

 amongst the decayed wood till they reached the 

 ground ; and there deriving nourishment, swelled, 

 united, and became as the bole of the tree, filling up 

 the cavity, and displacing all the mouldering wood 

 till the whole is now nearly a solid tree." And Pro- 

 fessor Balfour's account of the Mountain Ash at Pres- 

 tonhall might stand for a literal description of the Elm 



