The British Vegetation Committee. toi 
excursion was a profitable one. The geographical position of 
Aberystwyth (April, 1911) with its long railway journey naturally 
produced a small meeting, but those members present spent the 
greater part of three days in the field under the guidance of Professor 
Yapp. One day was given to Borth, an extensive tract of lowland 
bog, which on its seaward margin is now being invaded by estuarine 
mud, sand, and banks of shingle, each bearing its distinctive 
vegetation. Another day was spent in the extensive oakwoods 
between Aberystwyth and Devil’s Bridge, which are of the Q. 
sessiliflora type and very uniform, but present a series of interesting 
variations in the neighbourhood of springs and flushes. 
Nomenclature. 
The proposal to discuss phytogeographical nomenclature at the 
International Congress of Botanists at Brussels in 1910 gave the 
Committee an opportunity of formulating its views. On the 
invitation of the Reporters of the Commission of Phytogeographical 
Nomenclature (Professors Flahault and Schroeter), several members 
took part in an attempt to formulate the general view of the 
Committee. At the Cambridge meeting (April, 1909) certain theses 
were put forward for discussion with the result that a scheme was 
elaborated and submitted to the Reporters, and was later printed in 
the“ Reports and Propositions on Phytogeographical Nomenclature” 
for submission to the Congress. The crux of this document was : 
“that the term plant-formation should be applied to the fundamental 
unit of vegetation ” and “ that the view put forward by Moss 
(Geographical Distribution of Vegetation in Somerset, 1907, p. 16) 
which regards the plant-formation as the series of natural phases 
of vegetation occurring in a given habitat, is strictly in line with 
its historical development, since it emphasises the habitat as 
defining the formation.” This concept led to correspondence with 
the Reporters, who adopted the definition of E. Warming (Oncology 
of Planets, 1909), or, as they expressed it, “we can consider a 
formation as an actual expression of certain conditions of life 
independent of floristic composition.” They also contended that 
Moss’s view introduces hypotheses and subjectivity. The later 
publication “ Fundamental Units of Vegetation ” by Dr. Moss (1910) 
appeared about this time, and presented an historical inquiry into 
the use of “ plant-formation ” and other terms, and the view put 
forward there (p. 36) seemed to the Committee to express the 
general concept so well that they adopted it and submitted (January, 
1910) a set of resolutions in support, which were published in the 
“ Reports and Propositions” along with an appendix—“ Criticism 
of the attempt to determine plant-formations by ‘ growth-forms ’ 
(Warming, 1909),” by A. G. Tansley and C. E. Moss. 
Several members of the International Commission voted in 
favour of accepting the British Committee’s view of the concept of 
the plant-formation, but at an informal meeting of phytogeographers 
which took place in Brussels during the sittings of the Congress, at 
which the British Committee was represented by Mr. A. G. Tansley, 
it became clear that no general agreement on this point could be 
hoped for, and the Reporters very wisely decided not to put forward 
