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 1/2 per cent. per annum, while England increases over 1-1/2 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.

Why then has this fertile and beautiful country only a small fraction of the number of inhabitants that formerly lived in it?  That it is not caused by the climate being unfavourable to man is clear, for this district is free from the intense heat and the pestilential fevers of the low lands which lie nearer the sea.

It is a noticeable fact that the remains of the old settlements generally lie above the district where the banana grows; and the higher we rise above the sea, the more abundant do we find the signs of ancient population, until we reach the level of 8,000 feet or a little higher.  The actual inhabitants at the present day are distributed according to the same rule, increasing in numbers, according to the elevation, from 3,000 to 8,000 feet, after which the severity of the climate causes a rapid decrease.

In making these observations, I leave out of the question the hot unhealthy coast-lands of the tierra caliente, and the cold and comparatively sterile plains of the tierra fria, and confine myself to that part of the country which lies between the altitudes of 3,000 and 8,000 feet, between which limits the European races flourish under circumstances of climate which also suited the various Mexican races, who probably came from a colder northern country.  Now, if we begin to descend from the level of the Mexican plateau—­say 8,000 feet above the sea—­we find that less and less labour will provide nourishment for the cultivator of the soil, until we reach the limit of the banana, where the inhabitants ought to be crowded together like Chinese on their rice-grounds, or the inhabitants of Egypt in the time of Herodotus.  Exactly the opposite rule takes effect; the banana-country is a mere wilderness, and the higher the traveller rises the more abundant become both present population and the remains of ancient settlements.