88 BAHIA BLANCA. [cHarp. v. 
conclude, against anterior probability,* that among the mam- 
malia there exists no close relation between the bulk of the 
species, and the quantity of the vegetation, in the countries 
which they inhabit. 
With regard to the number of large quadrupeds, there cer- 
tainly exists no quarter of the globe which will bear comparison 
with Southern Africa. After the different statements which 
have been given, the extremely desert character of that region 
will not be disputed. In the European division of the world, 
we must look back to the tertiary epochs, to find a condition of 
things among the mammalia, resembling that now existing at 
the Cape of Good Hope. Those tertiary epochsy which we 
are apt to consider as abounding to an astonishing degree with 
large animals, because we find the remains of many ages accu- 
mulated at certain spots, could hardly boast of more large 
quadrupeds than Southern Africa does at present. If we 
speculate on the condition of the vegetation during those epochs, 
we are at least bound so far to consider existing analogies, as 
not to urge as absolutely necessary a luxuriant vegetation, 
when we see a state of things so totally different at the Cape 
of Good Hope. 
We knowyt that the extreme regions of North America, many 
degrees beyond the limit where the ground at the depth of a few 
feet remains perpetually congealed, are covered by forests of 
Jarge and tall trees. In a like manner, in Siberia, we have 
woods of birch, fir, aspen, and larch, growing in a latitudet 
(64°), where the mean temperature of the air falls below the 
freezing point, and where the earth is so completely frozen, that 
* If we suppose the case of the discovery of a skeleton of a Greenland 
whale in a fossil] state, not a single cetaceous animal being known to exist, 
what naturalist would have ventured conjecture on the possibility of a car- 
cass so gigantic being supported on the minute crustacea and mollusca living 
in the frozen seas of the extreme North? 
+ See Zoological Remarks to Capt. Back’s Expedition, by Dr. Richardson. 
He says, “ The subsoil north of lafitude 56° is perpetually frozen, the thaw 
on the coast not penetrating above three feet, and at Bear Lake, in latitude 
64°, not more than twenty inches. The frozen substratum does not of itself 
destroy vegetation, fur forests flourish on the surface, at a distance from the 
coast.” 
t See Humboldt, Fragmens Asiatiques, p. 386: Barton’s Geography of 
Plants: and Malte Brun. In the latter work it is said that the iimit of the . 
growth of trees in Siberia may be drawn under the parallel of 70°. 
