Head-hunting and associated Customs--“Mother-right” and Age-grade Systems--Property Rights--Sex Relations. The social organization of the Formosan aborigines presents many points of interest, but the four which most forcibly impress the visitor or student of aboriginal customs, and which, taken together, constitute a somewhat unique system, are the following: (_a_) _Head-hunting_ and the point of view of the tribes-people regarding this custom. (_b_) “_Mother-right_” more fully developed than is usual, even among primitive people, at the present time. (_c_) The _Communal System_--that of holding property in common--which exists among several of the tribes. (_d_) The _Chastity_ and _Strict Monogamy_ customary among these “Naturvölker”; habits which strikingly impress one who goes among them after having spent some time in China or Japan, or in the Chinese and Japanese towns and villages in the “civilized” part of the island. One, or more, of these customs naturally exists among primitive peoples in various parts of the world; it is the combination of these, welded into a well-defined social organization, that makes the latter unique. That “head-hunting” should be included under the head of “social organization” may seem perhaps a contradiction in terms--head-hunting not being exactly a social custom. I think, however, that anyone who has lived among a head-hunting tribe will realize how closely this custom is interwoven with the fabric of their whole social organization. It regulates the social and political standing of the men of the tribe; it is directly connected with marriage--no head, no wife; and is reflected in the games, the songs, and the dances of the people. Moreover head-hunting is regulated by a code as rigid as the code of “an officer and a gentleman” in so-called civilized society--and is rather less frequently broken.