Phylogeographical Excursion in the British Isles. 21 
of meeting in the field workers from different countries are, in the 
opinion of the present writer, absolutely essential to progress in the 
present position of the subject. The fruits of this particular expe- 
dition will become apparent in the future, while the stimulus 
afforded to the British workers both by the kindly appreciation and 
by the keen criticism of the visitors, will certainly be very marked. 
The organisation of the present excursion has led to a deter- 
mination on the part of the foreign visitors to organise similar 
expeditions in their own countries. Professors Clements and 
Cowles have decided to arrange an international excursion in the 
States in August and September, 1913; and Professor Schröter, 
Professor Massart and Dr. Ostenfeld have in view international 
excursions in Switzerland, Belgium and Denmark in 1915, the 
year of the International Congress in London, when the American 
botanists expect to be again in Europe. There was also talk of an 
International Phytogeographical Society. Such a society, if it 
were given a suitable organisation, would be of the greatest service 
in advancing the subject, which is nearly ripe for an effort of this 
kind. 
A. G. TANSLEY. 
