Malthus compares this tendency with the _actual increase_ of man in such countries as China and Japan. He observes that it may fairly be doubted whether the best directed efforts of human industry could double the agricultural produce of China even once, in _any_ number of years. The difference between the time of doubling, which has taken place of late in some twenty or thirty years, in North America, and in our Australian colonies, when compared with the slow increase of the Chinese population, gives the most complete view of the case that can be obtained. In countries which are naturally healthy, and where the _preventive_ check is found to prevail, too, with considerable force, the _positive_ check, as Malthus observes, will prevail very little, and the mortality will be small; but in _every_ country some of the checks are and will always continue to be, in constant operation: so that mankind has only a _choice_ of evils, for we cannot possibly escape from _some_ of the population checks, which are inevitable. In his third chapter our author reviews the population checks in the lowest stage of human society; and shows how impossible it is for such unfortunate peoples as the natives of the Tierra del Fuego, or of Van Diemen’s Land, to increase rapidly in numbers, owing to their extreme ignorance of the laws of nature. In New Zealand, Captain Cook found the checks to population to be war, and starvation so great as to prompt to cannibalism, in a country where, as it is at present colonized by a civilized people, the deaths seem not to exceed fifteen per 1,000 annually, and population doubles in about twenty years or less, without counting immigrants. In Mr. Malthus’ day, there still existed large numbers of those unfortunate races of American Indians, which are now so rapidly disappearing in the modern “struggle for existence” with civilised Europeans. Then, as now, these tribes lived principally by hunting and fishing, most narrow modes of subsistence. The mortality of infants among such tribes was always enormous, and the Jesuit missionaries mentioned how that the Indians of South America were subject to perpetual diseases for which they knew no remedy; scarcely ever did the individuals of such tribes attain to an advanced age; and the checks to population among them were chiefly of the _positive_ kind—plagues, starvation, brutal wars, and disease. The North American Indians, too, lived in such a state of filth and over-crowding in their huts, that every infectious disease carried off vast numbers. Cannibalism, according to Captain Cook, as seen in New Zealand and other islands, originated in the fearful privations experienced by such peoples when their numbers were pressing on the food supplies.