BOTANICAL INFORMATION. 203 
annual attack of the scythe in early summer ; but we require 
its presence, as a character, only in those spots which remain 
uninvaded by scythe or ploughshare; and in such spots we 
seldom seek it in vain, until arriving about the line where cli- 
mate itself arrests the ascent of agriculture. 
_ These two regions may be again divided, each into two sub- 
ordinate zones. For a suitable division of the agrarian region, 
we must again look to the artificial characters impressed upon 
its surface by the industry of man, who has so extensively 
changed those antecedent characters which were given by na- 
ture. Accordingly, I take the presence or absence of wheat- 
fields, as the leading test of distinction between a Lower 
Agr arian Zone and a Higher Agrarian Zone ; the upper por- 
tion of the region, for a considerable breadth, being wholly 
without wheat-fields. The limit of wheat appears not to cor- 
respond with the limit of any very conspicuous native plant. 
So far, the former may be deemed less suitable to the object 
In view; but it is a more general test, and therefore more 
applicable in practice, than any single native plant would 
prove.” 
* * * * 
British and Polar Botany.—* From the preceding enumera- 
tion of their species, it appears that the frigid coasts of the 
Polar seas, beyond the seventy-second degree of north latitude, 
Support an extremely scanty flora, including only a hundred 
and thirteen species, so far as hitherto ascertained. Most of - 
these are perennial herbs, of dwarf stature. If they attain any 
considerable size, it is only in the horizontal direction, by form- 
ing tufts, or by branching and spreading over the surface of 
the ground, Nothing is seen to rise with tall stems, like those 
of our Butomus or Digitalis ; nor are there any slender climb- 
'ng plants, like the Tamus or Bryonia. Trees are utterly 
Unknown; and the few shrubs which exist here, are those of 
the most humble growth, belonging to the orders of Amen- | 
taceæ and Ericaceæ. The general character of the floral land- 
"cape must be widely dissimilar from that of the British 
