128 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
of the very opposite qualities. Taking everything into consideration, 
we question much whether any other of our forest trees is of greater 
or even equal value with the plane for town planting. 
The Maidenhair Tree (Ginkgo biloba).—A prolonged visit to 
the very worst smoke-infested slums of London, has now quite 
convinced me that the maidenhair or ginkgo tree is one of the most 
valuable that can be planted in the impure atmosphere of a town 
garden. Few trees, | am fully aware, can compare with the one 
in question for withstanding the deleterious effects produced on 
vegetation generally by coming in too close contact with the 
impurities of our great centres of industry. The ample delicate 
green foliage betrays—even late in the season, and when about to 
be cast off—little evidence of the fierce struggle that must almost 
constantly go on between vegetation and the smoke and filth of our 
towns and cities. That the thick leathery leaves and strong con- 
stitution of the tree play an important part in keeping it free from 
disease is clearly evident, while the fact of the leaves being renewed 
annually must go a long way towards casting off the sooty nodules 
which work such havoc on the tender foliage of most trees. 
At no less than five places in and around the great metropolis— 
and such places, too, where one is almost stifled with the fumes from 
chimneys—the maidenhair tree may be seen almost in as fresh and 
flourishing a condition as those enviable specimens on the Isle of 
Man ; indeed, about as large trunks as can be seen anywhere are 
growing in the smoke of Chelsea. Not only asa standard tree is the 
maidenhair valuable, but it is also one of the prettiest wall plants 
with which I am acquainted, and how many bare ugly erections of 
brick and stone in our city streets want a bit of greenery I would 
not like to say. 
The Ailanthus, or Tree of Heaven (Adlanthus glandulosa), may be 
seen in a flourishing condition in many of the London streets and 
byeways. By its rich green spreading foliage, the Ailanthus is, 
during the summer months, a great favourite with lovers of sylvan 
scenery, the leaves in many cases reaching to a length of fully 
2 feet. It is a tree of very rapid growth when suitably placed as 
regards svil and situation, shoots nearly 2 feet being often produced 
in a season. 
Tt has been largely planted in many Continental cities, and has 
proved itself one of the few trees that are capable of withstanding 
the impurities of a town atmosphere. The greenish-white, incon- 
spicuous flowers, are freely produced, and are succeeded by 
