The other is called _jus sanguinis_, or the law of blood. This is the law that is followed in ordinary European civil law codes. According to this law, a person’s nationality or citizenship depends on the citizenship of his parents. The United States has adopted this rule in the case of children born abroad of parents that are American citizens. Each law has its advantages. It is certainly better to consider that the child of an American business man residing in China at the time the child is born is an American citizen than it would be to consider that the child was a subject of the Chinese Empire. This law of blood, like many other rules of the civil law, goes back to such a fundamental human instinct that any other way of dealing with this situation than the one it suggests would seem wrong to us. The law of the land, on the other hand, has very distinct advantages as well, which can also be illustrated from our American situation. A Russian man and woman, let us say, succeed in escaping persecution at home and come to this country to live. We prefer to think that their children, born on American soil and brought up under American institutions, are Americans, and we have made this the cardinal principle of American citizenship. It would be too late now to attempt to alter this law, even if we wished to do so, because it is firmly rooted both in statute law and in our fundamental conception of the meaning of America. And yet we find it convenient and right to use the opposed law of nationality, the law of blood, in such a case as a child born in China of American parents. If we find it necessary to adopt into our own statutes a provision so contrary to our general citizenship law as this law of blood, we cannot consistently object when another country adopts it as its principle of citizenship. The difficulty has been met hitherto by allowing the child to choose which nationality it wishes to keep when it becomes twenty-one, or attains its majority, and by holding it subject until that time to the law of whichever country it happens to be in. This at least is the way the situation works out, although there has never been any international ruling on the subject. If the child were in France, the French authorities applied the French law; if it were in America, the American authorities applied the American law, and when the child became of age, it made its election, and thereafter was held to be a citizen of whichever country it elected. It was considered to be so clear a fact that this election was something that the child alone could do, that the fact that the father took the child from one country to another was held over and over again not to affect the child’s right to chose for itself when it became of age. Theoretically we hold that there can be no dual citizenship of the naturalized citizen or of the child born in America if he elects American citizenship. The records are not altogether clear if we stand ready to enforce this.