HEWETT COTTRELL WATSON. 261 
into 88 subprovinces and 112 counties or vice-counties. The 
vertical range of the species he registers by means of two regions of 
climate and altitude, each divided into three zones. The Agrarian 
region includes that part of Britain in which it is possible, so ane as 
climate is concerned, to cultivate the cereal grasses and potatoes. 
It of course includes the whole area of the ge at sea-level from 
north to south ; and the hills up to about 600 yards in the North 
of England, and 400 yards in the North 7 Scotland. All above 
this is mountain, heather, and rock, with a temperature like that 
of the low levels in Arctic latitudes. This u pper region he called 
the Arctic region, and the zones Superarctic, Midarctie and Infer- 
arctic, Superagrarian, Midagrarian and Inferagrian. The Infer- 
agrarian zone, for instance, Calas all the low-level country south 
of the estuaries of the Humber and the Mersey. He estimated that 
average annual temperature sinks at the rate of one degree 
Fahrenheit for every hundred yards of ee and that in 
Britain the range of mean annual temperature is from 52° to 84°, 
ah he 
historical point of view, classifying them into Natives, Colonists, 
Denizens, and Aliens, according to whether they —— to have 
h een intro- 
duced by human agency acting directly or indirectly. And finall 
English, Atlantic, Germanic, Scotch, or Highland, according to 
? : ' 
provinces. In the three volumes of the ioe 1988-1870) 
a mass of additional information obtained after the publication of 
the ‘Cybele’ is incorporated, and the distribution ta the species 
beyond the bounds of Britain worked out. y> 
‘Topographical Botany,’ 2 volumes, 1873-1874, the horizontal 
distribution of the species is —— through the 112 vice- counties. 
Altogether the earlier small octavos run on t out sixteen 
hundred pages, and the later poor of larger ais . four 
© 
. as 0 
point bearing upon the evolution sane which attracted his 
attention from an early date, and on which he strongly advocated 
the views which are now generally current long before Darwin 
were dealing with species as if they possessed a clearly-mar 
and definitely separable individuality, their uncertain 
inequality formed one of his favourite theses. An article on the 
