ALTERED CONDITIONS OF TREE GROWTH 7 



including the Plane, Acacia, Sumach, and others, being 

 better adapted for withstanding the deleterious effects 

 of an impure and heated atmosphere. It is also a 

 curious fact that varieties have succeeded, in several 

 cases at least, better than the species, and we have 

 good examples of such in Platanus orientalis acerifolia 

 (the maple-leaved or London Plane), Fraxinus excelsior 

 pendula (the Weeping Ash), Populus fastigiata (Upright 

 Poplar), Cut -leaved varieties of Pyrus, Broad-leaved 

 Hollies, Weeping Elm, Variegated-leaved Sycamore, 

 and several dwarf forms of Acacia and double-flowering 

 varieties of the Cherry and Scarlet Thorn. 



Judging from the age and size of existing trees, it 

 is evident that a century and more ago several species, 

 including the Lebanon Cedar, Beech, Oak, and Scotch 

 Pine, flourished in the London area ; but they are now 

 gradually dying out or have been ousted to the more 

 favourable conditions of the suburban districts. At 

 one time the noblest Cedars of Lebanon grew in the 

 Chelsea district, Elms at Lambeth, and Oak, which 

 was used for boat-building, in Regent's Park ; but these 

 are gradually disappearing, until now of the Cedar 

 hardly a healthy tree remains in London, while the 

 old Elms in Hyde Park and the grounds at Lambeth 

 Palace are sadly diseased and broken about, and hardly a 

 specimen of the British Oak can now be found in Regent's 

 Park, where two centuries ago it was abundant. 



The native Scotch Pine in considerable numbers 

 attained to a large size on Hampstead Heath, but few 

 of the original specimens now exist, and those that 

 remain are gradually dying and becoming infested with 

 fungus and insect pests. The trees in Colder 's Green 

 Park are, however, in a flourishing and healthy con- 

 dition, and many are of exceptional size, especially the 



