[369] MORGAN, _Proceedings of the American Academy of Arts and Sciences_, VII, 469; _Ancient Society_, 69, 424 ff.; _cf._ STARCKE, _op. cit._, 323; WESTERMARCK, _op. cit._, 317. [370] PESCHEL, _Races of Man_, 224; WESTERMARCK, _op. cit._, 317, 318; also DARWIN, _Animals and Plants under Domestication_, II, 124; LUBBOCK, "Customs of Marriage and Systems of Relationship among the Australians," _Jour. Anth. Inst._, XIV, 300. [371] MAINE, _Early Law and Custom_, 228. [372] DARWIN, _op. cit._, II, 103, 104, accepts HUTH'S view (_Marriage of Near Kin_), that there is no "instinctive feeling in man against incest any more than in gregarious animals." Starcke's argument leads up to the conclusion that the basis of exogamy is to be sought in the causes which produced the clan; for between the clans of a tribe exogamy almost always prevails, and, without exception, clanless tribes are "endogamous or at least not exogamous." Furthermore, tribes divided into clans are usually endogamous as to the tribe.[373] Now, prohibitions are found which cannot be due to "exogamy as a definition of the clan;" such is the prohibition of marriage between mother and son where agnation is in force, and "between father and daughter where the uterine line prevails." Since, therefore, "exogamy as a definition of the clan cannot directly produce these prohibitions, which are found wherever exogamy occurs, and in some instances where it is absent," the inference follows that exogamy must have its origin in the abhorrence of close intermarriage and the ideas to which that is due. But these ideas are not necessarily the same as those underlying "the various prohibited degrees of marriage which are now in force;" nor do they imply that the injuriousness of such unions is the ground of the aversion. "In a community in which marriage takes place between consumptive and syphilitic persons, and those affected by hereditary disease, without being condemned by public opinion, and still less by the law, it cannot be said that the condemnation of incest is founded on our regard for posterity."[374] In harmony with his view that marriage is juridical, not founded on sexual relations, he finds the origin of the horror of marriage between near kindred in the legal incongruity of such unions and in their danger to the peculiar constitution of the ancient family itself. Marriage between a brother and sister or between a mother and son would usually be impossible because the "son possesses nothing which he could offer to the father as purchase-money." To accomplish the purpose by force would be an "unheard-of crime among savages." A connection between a father and daughter would seldom occur, "since a father is unwilling to renounce the advantages of bestowing his daughter in marriage."[375] "If in this way an impression arises that there is something unusual and incompatible with other ideas in marriage between such persons,