The Meeting of the British Association at York. 185 
Pseudo-Monocotyledons ” was read immediately after that by Mr. 
Tansley and Miss Thomas, sought to show by a consideration of 
bulbous and rhizomatous species of Peperomia and Cyclamen, that 
clues may be obtained to the mode of evolution of the true Mono¬ 
cotyledons, the two cotyledons assuming different functions. Thus, 
in his view the single cotyledon of the Monocotyledon represents 
only one of the two cotyledons of the typical Dicotyledon, the other 
being represented by the first foliage leaf. Miss Sargant found 
herself unable to accept this view of the matter. 
Ecological Papers. 
On Thursday morning, after the President’s Address, and in 
the afternoon, several papers were taken, dealing with vegetation 
in different parts of the world. 
Mr. Seward communicated a paper by Professor H. H. W. 
Pearson of Cape Town, on “ Some South African Cycads : their 
Habitats, Habits and Associates,” in which the Cycad region is 
described and contributions are made to the natural history of 
Enceplialartos cycadifolius, E. Altensteinii and Stangeria. In a letter 
received by Mr. Seward from Professor Pearson after the paper 
had been communicated, some observations are recorded which 
make it probable that Encephalartos is pollinated by insects. 
Mr. Hugh Richardson read a paper on “The Vegetation of 
Teneriffe,” in which he brought out the zoning of vegetation round 
the peak of that island and gave some interesting data on the 
colonisation of lava streams. 
Dr. T. W. Woodhead furnished a very complete account of 
the history of vegetation-study in Switzerland, a country in which 
this branch of botanical work is in many respects very advanced. 
Dr. Woodhead’s paper was illustrated by an excellent set of Swiss 
publications on the subject. 
Mr. C. E. Moss contributed a paper on the “ Succession of 
Plant-Formations in Britain,” in which he dealt with succession on 
the coast (sand dunes and mud fiats) and in lowland peat; also 
with the woodland, scrub and heath formations on limestone. He 
pointed out that the open associations at the beginning of a suc¬ 
cession are often dominated by one plant, the intermediate associa¬ 
tions are composed by many species, while the final closed 
associations again have typically a single dominant. 
