ga, Samoa, and the rest—where, restrained within limits by surrounding seas, the inhabitants have become united more or less closely into aggregates of considerable sizes. The other is furnished by ancient Peru, where, before the time of the Incas, semi-civilized communities had been formed in valleys separated from each other "on the coast, by hot and almost impassable deserts, and in the interior by lofty mountains, or cold and trackless punas." And to the implied inability of these peoples to escape governmental coercion, thus indicated by Squier as a factor in their civilization, is ascribed, by the ancient Spanish writer Cieza, the difference between them and the neighboring Indians of Popayan, who could retreat, "whenever attacked, to other fertile regions." How, conversely, within the area occupied, the massing of men together is furthered by ease of internal communication, is sufficiently manifest. The importance of it is implied by the remark of Grant concerning equatorial Africa, that "no jurisdiction extends over a district which can not be crossed in three or four days." And such facts, implying that political integration may increase as the means of going from place to place become better, remind us how, from Roman times downward, the formation of roads has made larger social aggregates possible.
Evidence that a certain type of physique is requisite has been elsewhere given.[1] We saw that the races which have proved capable of evolving large societies have been races previously subject, for long periods, to conditions fostering vigor of constitution. I will here add only that the constitutional energy needed for continuous labor, without which there can not be civilized life and the massing of men that accompanies it, is an energy not to be quickly acquired under any conditions or through any discipline, but to be acquired only by inherited modifications slowly accumulated. Good evidence that in lower types of men there is a physical incapacity for continuous labor, is supplied by the results of the Jesuit government over the Paraguay Indians. These Indians were reduced to industrial habits, and to an orderly life which was thought by many writers admirable; but there eventually resulted the fatal evil that they became infertile. Not improbably, the infertility habitually observed in savage races that have been led into civilized habits, is consequent on taxing the physique to a degree greater than it is constituted to bear.
Certain moral traits which favor, and others which hinder, the union of men into large groups, were pointed out when treating of "The Primitive Man—Emotional."[2] Here I will reillustrate such of these as concern the fitness or unfitness of the type for subordination, "The Abors, as they themselves say, are like tigers, two can not dwell in one den," writes Mr. Dalton; and "their houses are scattered singly, or in groups of two and three." Conversely, some of the African races not only yield when coerced, but admire one who coerces them;
