297 
Pensions of the British Flora . /. 
terms of Willis’s ‘ Age and Area ’ theory of distribution. It is shown that 
by trying to discover disturbing factors and allowing for these, the results 
obtained are consistent with this hypothesis in its broad outlines, although 
on a first analysis the theory may not appear particularly applicable. 
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—--- ( 1916 ) : The Plants of the Late Glacial Deposits of the Lea Valley. Quart. Journ. Geol. 
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- ( 1922 ) : Chapter XIV in Willis’s ‘ Age and Area’. Camb. Univ. Press. 
