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 fría_, 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. I suppose the reason of this is to be found in the habits and constitution of the tribes who colonized the country, and preferred to settle in a climate resembling that of their native land, without troubling themselves about the extra labour it would cost them to obtain their food. The European invaders have acted precisely in the same way; and the distribution of the white and partly white inhabitants of the country follows the same rule as that of the Indians.