94 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



The great Cedar of Lebanon, which died about fifteen years 

 ago in the Chelsea Physic Garden, and was suffered to remain 

 for several seasons, a melancholy spectre, until the corpse 

 teemed with wood-lice and other concomitants of corruption, 

 was planted there in the reign of Charles II., when Chelsea was 

 a quiet waterside village amid green fields and hedgerow timber. 

 Plant a cedar or any other conifer there now, and, admirably as 

 the garden is kept, it would defy the skill of the curator and his 

 staff to keep it alive. And, as with cedars and all other conifers, 

 whereof the resinous exudation makes them peculiarly impatient 

 of impure air, so with our native or naturalised trees ; it is useless 

 to attempt planting oak, beech, ash, sycamore, horse-chestnut, 

 sweet chestnut, lime, or elm, for none of these can pass through 

 adolescence undeformed, and most of them will die in infancy. 



Now, as to the material for keeping London leafy. Practically 



there are but four kinds of forest trees to work with : of humbler 



growths we will speak presently. These four are the Oriental 



plane, the Ailanthus, the Robinia or false acacia, and two or 



three species of poplar. The behaviour of the plane as a street 



tree is certainly remarkable. Patient of extreme drought about 



its roots, and escaping the searing winds of British spring-time by 



leafing very late, it avails itself of the excessive heat in London 



to ripen its annual growths, which it can only do imperfectly in 



our more northerly counties. It rids itself of the impurities 



which winter fogs deposit on its bark by shedding its skin and 



appearing each year in bright, new covering of satiny texture. 



As for soil, it is as little exacting as any living thing can be, 



subsisting even upon the jumble of brick-bats, old tins, and 



paper rubbish which form the staple of the Victoria Embankment. 



The Tree of Heaven (Ai'/anfhus glandulosa) is as valuable for 



street planting as the plane, but is far less often seen in good 



condition, owing to neglect in training it to a single leader. The 



name of "Tree of Heaven," usually given to it, is really the 



name of a loftier tropical species, called in the Amboyna language 



aylanto, that is, "tree touching the sky." A native of China, 



the Ailanthus revels in our sun-baked streets, but it is not until 



late in summer that its fine pinnate foliage attains full luxuriance, 



It is dioecious, and only the female trees should be used for street 



planting, as the flowers of the male plant exhale a disagreeable 



rammish odour in hot weather. The value of Robinia, which we 



call acacia and the Americans call the locust tree, consists in its 



