Physically, as may be judged from the accompanying tables, there is a wide margin for dissimilarity among these tribes. Their appearance is nearly as varied as their speech, more so in fact, in that there is much diversity of type even among individuals of the same speaking-group. I have seen a Boro as dark as a Witoto, while his fellow - tribesmen may be yellow as a Chinaman. It is, of course, possible that the darker Boro are sons of Witoto women. The custom prevalent in all the tribes of adopting the young children captured from their enemies, makes of necessity for great changes in type even in one household, so that despite the preference for group endogamy that undoubtedly exists there are few households where cross-breeding is not in evidence.

In stature the Indian is small, which I take to be a result of depression due to his forest environment; but the body is wellbalanced and upright. Among the tribes I visited the Andoke as a speaking-group were, so far as I could observe, the largest in build and the tallest. The Okaina may possibly come into the same scale. The Karahone represent the mean, while the Maku are invariably small, a low class and badly-fed people. The average measurements of the tribes are best gathered from the types tabulated. I made the average height to be for men 5 feet 6 inches; and for women 4 feet 10 inches.