Portions of the British Flora. /. 
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by the map is the remarkably regular diminution of the flora from the south¬ 
east, where it is concentrated, towards the north-west, where it is sparse. The 
mass distribution suggests a general invasion and migration north-westwards. 
Diagram i. Distribution of 266 plants of the British Flora confined to England and Wales, 
Whether the immigration of the British flora as a whole followed this 
direction only further analysis will show, but a clue which seems worth 
following is provided by the map before us. 
There is at present little evidence to show whether any of these 
