In the upper portion of this district, where the banana no longer flourishes, nutritious plants produce an immense yield with easy cultivation. The _yucca_ which produces cassava, rice, the sweet potato, yams, all flourish here, and maize produces 200 to 300 fold. According to the accepted theory among political economists, where the soil produces with slight labour an abundant nutriment for man, there we ought to find a teeming population, unless other counteracting causes are to be found. The history of the country, as far as we can get at it, indicates a movement in the opposite direction. Judging from the numerous towns the Spanish invaders found in the district, the numbers of armed men they could raise, and the abundance of provisions, we must reckon the population at that time to have been more dense than at present; and the numerous ruins of Indian settlements that exist in the upper temperate region are unquestionable evidence of the former existence of an agricultural people, perhaps ten times as numerous as at present. The ruins of their fortifications and temples are still to be seen in great numbers, and the soil all over large districts is full of the remains of their pottery and weapons. How far these settlements were depopulated by wars before the Spanish Conquest, it is not easy to say. During the Conquest itself they did not offer much resistance to the European invaders, and consequently they escaped the wholesale destruction which fell upon the more patriotic inhabitants of the higher regions. Since that time the country has been peaceable enough; and even since the Mexican Independence, the wars and revolutions which have done so much injury to the inhabitants of the plateaus have not been much felt here. In reasoning upon Mexican statistics we have to go to a great extent upon guess-work. A very slight investigation, however, shows that the calculation made in Mexico, that the population increases between one and two per cent. annually, is incorrect. The present population of the country is reckoned at a little under eight millions; and in 1806, it seems, from the best authorities we can get, to have been a little under six millions. Even this rate of increase, one-third every half-century, is far above the rate of increase since the Conquest; for, at that rate, a population a little over a million and a quarter would have brought up the number to what it is at present, and we cannot at the lowest estimation suppose the inhabitants after the siege of Mexico to have been less than three or four millions. So that, badly as Mexico is now going on with regard to the increase of its population, about ½ per cent. per annum, while England increases over 1½ per cent., and the United States twice as much, we may still discern an improvement upon the times of the Spanish dominion, when it was almost stationary.