stay in these regions during summer is nearly rendered impossible by
the enormous number of mosquitoes with which the air is infested.

A table drawn up by Dr. Arnell, to be found in _Redogoerelse foer de
svenska expeditionerna till mynningen of Jenisej ar 1876_,[212]
shows the distribution of the most important varieties of trees.
From it we see that on the Yenesej the birch (_Betula odorata_,
BECHST.), the fir (_Pinus obovata_, TURCZ.), the larch (_Pinus
larix_, L.), and the juniper (_Juniperus communis_, L.), go to 69 deg.
35' N.L. (that is to say to the latitude of Tromsoe); the
sallow (_Salix caprea_, L.) to 68 deg. 55'; the bird's cherry
(_Prunus padus_, L.), and the Siberian pine (_Pinus sibirica_,
LEDEB.), to 66 deg. 30'; the aspen (_Populus tremula_, L.) to 65 deg. 55'
(the latitude of Haparanda); the pine (_Pinus sylvatica_,
L.) to 65 deg. 50', &c.

In the middle of the forest belt the wood appears to cover the whole
land without interruption, there being, unless exceptionally, no
open places. But towards the north the forest passes into the
treeless _tundra_ through bare spots occurring here and there, which
gradually increase, until trees grow only in valleys and sheltered
places, and finally disappear completely. Similar is the passage of
the forest to treeless regions (steppes), which at first are here
and there bestrewed with more or less detached groups of
broad-leaved trees, until they wholly disappear, and the land forms
an endless plain, out of whose fertile soil the warm summer sun
calls forth a great variety of luxuriant vegetable forms, whose
many-hued flowers, often large and splendid, clothe the fields with
the richest splendour of colour. Here is the true homeland of many
of the show-plants in the flower-gardens of Europe, as, for
instance, the peony, the Siberian robinia, the blue iris, &c.

If the Siberian wooded belt forms the most extensive forest in the
world, this flower-steppe forms the world's greatest cultivable
field, in all probability unequalled in extent and fertility.
Without manure and with an exceedingly small amount of labour
expended on cultivation, man will year by year draw forth from its
black soil the most abundant harvests. For the present, however,
this land, with its splendid capabilities for cultivation, has an
exceedingly scanty population; and this holds good in a yet higher
degree of the forest belt, which is less susceptible of cultivation.
At a considerable dis