26 INTRODUCTION. 
an earlier northern limit or cessation than those of the preceding 
type. Their terminal points or lines are very different among 
themselves ; some of the species being entirely limited to two or 
three of the most southern provinces of England; while other 
species occur in all the provinces of Britain, with an exception of 
two or three of the most northern; the great majority having 
their limits between these extremes. ‘Those species which extend 
into nearly all the provinces, except two or three of the northern, 
approximate very closely to the less general examples of the 
British type; and, in fact, there are cases where it becomes 
almost optional whether the species are to be referred to the one 
or to the other type. To the characters of lessened frequency and 
earlier termination northward, which distinguish the species of the 
English from those of the British type, must be added that of 
spreading into both the eastern and the western provinces of 
England, and without any very decided difference of comparative 
frequency towards the two sides of the island, beyond that 
which may be caused by the repellent influence of the western 
mountains, which necessarily tend to banish such species as are 
naturally adapted to low situations, in a warmer and drier climate 
than that of our mountainous districts. The name will not be mis- 
understood to indicate that all the species are peculiar to England, 
but is to be understood only as implying that the species are 
apparently adapted to the climate of England, either being 
restricted to that part of Britain, or being more prevalent there 
than in Scotland. Characteristic examples of the English type of 
distribution may be cited in Rhamnus catharticus, Ulex nanus, 
Tamus communis, Bryonia dioica, Hottonia palustris, Chlora per- 
foliata, Sison Amomum, Linaria Elatine, Ranunculus parviflorus, 
Lamium Galevbdolon, Hordeum pratense, Alopecurus agrestis, Ce- 
terach officinarum. 
3. The Scottish Type—This may be deemed the opposite of the 
English type; the distribution of the species referred hercto 
being characterised by a northern tendency, either by absolute 
limitation to Scotland or the north of England, or otherwise by a 
chief prevalence there and increased rarity southward. Parallel 
