a Origin of the British Flora. 
fauna and flora, and the relations these bear to the climatic 
changes through which this country has passed. 
Moreover, this life spent principally in tield, and moor, 
and forest has forced me to observe how each changing 
season is marked by corresponding adaptations in the 
animals and plants, such as enable the species to preserve 
themselves, to multiply, and to spread; or, if adaptation 
fails at any point, through some climatic irregularity, how 
sweeping and rapid may be the extermination of all except 
some few accidentally favoured individuals. While col- 
lecting seeds and fruits for comparison with the fossils 
I was compelled particularly to observe their many 
adaptations for dispersal, and also their times of ripening, 
and the abundance or scarcity of ripe seeds. 
It was impossible under such circumstances to avoid 
seeing the close connexion which must exist between the 
present geographical distribution of plants and animals 
and bygone changes in climate and in physical geography. 
Edward Forbes’ * essay was read and read again ; but it 
soon became apparent that his brilliant generalisations, 
though far in advance of the date when they were written, 
were only partially true. Much of his reasoning was 
fallacious. 
To explain the presence of Arctic and of Iberian plants 
in Britain, he showed that outliers of the Arctic flora stranded 
on our mountain peaks could be accounted for by an 
appeal to the climatic conditions of former days, when a 
similar flora covered the whole of our Islands, and was not 
confined to isolated mountains. He did not see, apparently, 
that the use of this reasoning precluded the use of the 
* ‘On the Connexion between the Distribution of the existing 
Fauna and Flora of the British Isles, and the Geological Changes 
which have affected their area, especially during the epoch of the 
Northern Drift.’—dZem. Geol. Survey, Vol. 1., pp. 336-432 (1846). 
