In the first place, it is believed, the direct evidence as to the existence of races living promiscuously in ancient and modern times will not stand the test of criticism.[324] Often the statements of writers and travelers prove on examination to be erroneous. Thus, for instance, Sir Edward Belcher's assertion, that among the Andaman Islanders "the custom is for the man and woman to remain together until the child is weaned, when they separate, and each seeks a new partner,"[325] has been "disproved by Mr. Man, who, after a very careful investigation of this people, says not only that they are strictly monogamous, but that divorce is unknown, and conjugal fidelity till death not the exception but the rule among them."[326] Sometimes the "facts adduced are not really instances of promiscuity." This appears to be true, as already seen, of the alleged Australian group-marriages. So also the "communism" practiced among the Cahyapós, "who seem to be the most numerous tribe of the central plateaux of Brazil," turns out on examination to be something very different from promiscuity, resembling more the "temporary" marriages already mentioned, though combined with polygyny. "The communism of wives among them," says Magalhães,[327] "is as follows: The woman as soon as she reaches the age at which she is permitted to have relations with a man, conceives by the one who pleases her. During the period of gestation and nursing she is maintained by the father of the child, who may have others in similar charge and these others during similar periods live in the same cabin. As soon as the woman begins to work she is free to conceive by the same man or she may procure another, the charge of supporting the earlier offspring passing to the latter."[328] This institution, it is clear, involves considerable social regulation. Indeed we are particularly warned that "by communism of women is not to be understood anything like prostitution.... This distinction is the more important for the proper comprehension of the savage family, since it is certain that in those same tribes where this communism exists, prostitutes are held in great displeasure." The custom "is a mode of family existence that they judge best according to their ideas and means of living." With it Magalhães contrasts the "exclusiveness" of the neighboring Guatos of the river Plate, in "Brazilian Paraguay," who are not monogamous, each man having "one, two, or three wives according to his ability in hunting, fishing, and the gathering of the different fruits which make up the base of their food." The women are exceedingly modest. "If a Guato woman brought us a fish, some game, wild fruit," or in any way sought "something of ours that she wanted, she did it always with her eyes fixed on the ground or turned toward her husband." The related Chambioás of the Amazon valley are even more severe. Among them women are burned for adultery; and in their "widows' men" they have