265 
male trees including those at Vienna and Montpellier.’’ May it 
not be that grafts were sent at the same time to Utrecht and 
have been lost sight of until the removal of the elm trees 
mentioned by Professor Went admitted more light and resulted 
in the better development of a grafted branch that had hitherto 
been too weak to flower? In the same way is it certain that 
male branches have not been grafted upon isolated female trees ? 
Apart from the interest attached to the fruits or seeds of 
female trees their decorative value is no greater than that of 
males whilst the latter are infinitely preferable for public gardens 
and for gardens attached to residences, owing to the abominable 
odour of the falling fruit of female trees in autumn. Unfortu- 
nately it is not possible to separate the trees before they flower 
therefore the selection of sex must be left to chance. Ginkgo 
biloba is a tree that might be more extensively employed than 
at present in schemes of decorative planting for it is very hardy, 
succeeds under a great variety of conditions, is not susceptible 
to disease and is rarely attacked by insects. Although the best 
development is attained by trees growing in a clear atmosphere, 
good results are obtained in towns, and even under the worst 
possible conditions of smoke and dust trees live for many years. 
There is a decrepit specimen growing behind a wall adjoining 
High Street, Brentford, where for many years it has been hemmed 
in by high walls and exposed to the dust and dirt of a busy town 
and constant stream of traffic. Yet it lives on. Well grown 
trees can be transplanted with safety and specimens 25 feet high 
have been moved at Kew without difficulty. 
Apart from the value of the edible seeds Ginkgo has little 
economic value, the timber being weak, of no special use, and 
too scarce to give it any place in commerce. 
XLI.—BUTTRESSES AS AN ASSISTANCE TO 
IDENTIFICATION. 
T. F. Cupp. 
It is a little strange that one of the most striking characteristics 
of trees in the tropical Rain Forests, namely the buttresses, 
should have received such scant attention. Works on plant 
geography as a rule give them but a brief notice, forest floras 
hardly refer to them at all and then only in very general terms, 
and collectors in their field notes accompanying specimens, rarely 
record even their presence. ; 2. 
Their function is generally considered to be in assisting to 
support the massive trunks, and where the subject is dealt with 
at any length, attention is generally directed to the stilt or prop 
roots of the Mangrove formation, or to record the huge 
dimensions of the largest plank buttresses. Mr. H. N. Whitford 
in his appreciative study of “The Vegetation of the Lamao 
