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SAT阅读试题:SAT Reading Comprehension Test 7
That large animals require a luxuriant vegetation, has
been a general assumption which has passed from
one work to another; but I do not hesitate to say that
it is completely false, and that it has vitiated the
5 reasoning of geologists on some points of great
interest in the ancient history of the world. The
prejudice has probably been derived from India, and
the Indian islands, where troops of elephants, noble
forests, and impenetrable jungles, are associated
10 together in every one's mind. If, however, we refer to
any work of travels through the southern parts of
Africa, we shall find allusions in almost every page
either to the desert character of the country, or to the
numbers of large animals inhabiting it. The same
15 thing is rendered evident by the many engravings
which have been published of various parts of the
interior.
Dr. Andrew Smith, who has lately succeeded in
passing the Tropic of Capricorn, informs me that,
20 taking into consideration the whole of the southern
part of Africa, there can be no doubt of its being a
sterile country. On the southern coasts there are some
fine forests, but with these exceptions, the traveller
may pass for days together through open plains,
25 covered by a poor and scanty vegetation. Now, if we
look to the animals inhabiting these wide plains, we
shall find their numbers extraordinarily great, and
their bulk immense. We must enumerate the elephant,
three species of rhinoceros, the hippopotamus, the
30 giraffe, the bos caffer, two zebras, two gnus, and
several antelopes even larger than these latter
animals. It may be supposed that although the species
are numerous, the individuals of each kind are few.
By the kindness of Dr. Smith, I am enabled to show
35 that the case is very different. He informs me, that in
lat. 24', in one day's march with the bullock-wagons,
he saw, without wandering to any great distance on
either side, between one hundred and one hundred
and fifty rhinoceroses - the same day he saw several
40 herds of giraffes, amounting together to nearly a
hundred. At the distance of a little more than one
hour's march from their place of encampment on the
previous night, his party actually killed at one spot
eight hippopotamuses, and saw many more. In this
45 same river there were likewise crocodiles. Of course
it was a case quite extraordinary, to see so many great
animals crowded together, but it evidently proves that
they must exist in great numbers. Dr. Smith describes
the country passed through that day, as 'being thinly
50 covered with grass, and bushes about four feet high,
and still more thinly with mimosa-trees.'
Besides these large animals, every one the least
acquainted with the natural history of the Cape, has
read of the herds of antelopes, which can be
55 compared only with the flocks of migratory birds.
The numbers indeed of the lion, panther, and hyena,
and the multitude of birds of prey, plainly speak of
the abundance of the smaller quadrupeds: one
evening seven lions were counted at the same time
60 prowling round Dr. Smith's encampment. As this able
naturalist remarked to me, the carnage each day in
Southern Africa must indeed he terrific! I confess it is
truly surprising how such a number of animals can
find support in a country producing so little food. The
65 larger quadrupeds no doubt roam over wide tracts in
search of it; and their food chiefly consists of
underwood, which probably contains much nutriment
in a small bulk. Dr. Smith also informs me that the
vegetation has a rapid growth; no sooner is a part
70 consumed, than its place is supplied by a fresh stock.
There can be no doubt, however, that our ideas
respecting the apparent amount of food necessary for
the support of large quadrupeds are much
exaggerated.
75 The belief that where large quadrupeds exist, the
vegetation must necessarily be luxuriant, is the more
remarkable, because the converse is far from true. Mr.
Burchell observed to me that when entering Brazil,
nothing struck him more forcibly than the splendour of
80 the South American vegetation contrasted with that of
South Africa, together with the absence of all large
quadrupeds. In his Travels, he has suggested that the
comparison of the respective weights (if there were
sufficient data) of an equal number of the largest
85 herbivorous quadrupeds of each country would be
extremely curious. If we take on the one side, the
elephants hippopotamus, giraffe, bos caffer, elan,five
species of rhinoceros; and on the American side, two
tapirs, the guanaco, three deer, the vicuna, peccari,
90 capybara (after which we must choose from the
monkeys to complete the number), and then place
these two groups alongside each other it is not easy to
conceive ranks more disproportionate in size. After the
above facts, we are compelled to conclude, against
95 anterior probability, that among the mammalia there
exists no close relation between the bulk of the
species, and the quantity of the vegetation, in the
countries which they inhabit.
