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 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 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 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, 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, 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 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 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 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 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 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 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 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 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 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.
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 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 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, 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 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.
- The author is primarily concerned with
- discussing the relationship between the size of mammals and the nature of vegetation in their habitats
- contrasting ecological conditions in India and Africa
- proving the large animals do not require much food
- describing the size of animals in various parts of the world
- explaining that the reasoning of some geologists is completely false
- The word ‘vitiated’ most nearly means
3. The flocks of migratory birds are mentioned to
- describe an aspect of the fauna of South Africa
- illustrate a possible source of food for large carnivores
- contrast with the habits of the antelope
- suggest the size of antelope herds
- indicate the abundance of wildlife
- The ‘carnage’ refers to the
- number of animals killed by hunters
- number of prey animals killed by predators
- number of people killed by lions
- amount of food eaten by all species
- damage caused by large animals
- The author makes his point by reference to all of the following except
- travel books
- published illustrations
- private communications
- recorded observations
- historical documents
Analysis and answers
Correct Answer:A : discussing the relationship between the size of mammals and the nature of vegetation in their habitats
Both the first and the last sentence of the excerpt indicate that the author is concerned with the size of mammals and the amount of vegetation. Hence answer A. (Note that strong words like ‘prove’ and ‘completely’ are not usually answers to primary purpose questions. This fact can help you eliminate answer choices.)
Correct Answer:C : impaired
‘Vitiated’ usually means ‘weakened’. Here the author argues that false ideas have ‘vitiated the reasoning of geologists’. False ideas would harm or ‘impair’ reasoning. Hence, answer C.
Correct Answer:D : suggest the size of antelope herds
The flocks are mentioned as part of a comparison. Herds of antelopes are compared to flocks of birds to indicate the size of the herds. The best answer is D.
Correct Answer:B: number of prey animals killed by predators
To be sure of the answer we need to read the sentence before the reference to carnage. The mention of predators such as the lion, panther and hyena, as well as the birds of prey, indicates that the author is thinking of all the animals that must be killed by these predators each day. Hence, answer B.
Correct Answer:E: historical documents
The author mentions travel books, illustrations (engravings), private communication (Dr. Smith informed the author personally), and he refers to recorded observations in various places. But there are no mentions of historical documents (only contemporary ones are mentioned). This makes E the correct answer.