In addition to the phratries and clans, another secondary group is frequently met with in Australian societies, which is not without a certain individuality: these are the matrimonial classes. By this name they designate certain subdivisions of the phratry, whose number varies with the tribe: there are sometimes two and sometimes four per phratry.[256] Their recruiting and operation are regulated by the two following principles. In the first place, each generation in a phratry belongs to different clans from the immediately preceding one. Thus, when there are only two classes per phratry, they necessarily alternate with each other every generation. The children make up the class of which their parents are not members; but grandchildren are of the same class as their grandparents. Thus, among the Kamilaroi, the Kupathin phratry has two classes, Ippai and Kumbo; the Dilby phratry, two others which are called Murri and Kubbi. As descent is in the uterine line, the child is in the phratry of its mother; if she is a Kupathin, the child will be one also. But if she is of the Ippai class, he will be a Kumbo; if the child is a girl, her children will again be in the Ippai class. Likewise, the children of the women of the Murri class will be in the Kubbi class, and the children of the Kubbi women will be Murri again. When there are four classes per phratry, instead of two, the system is naturally more complex, but the principle is the same. The four classes form two couples of two classes each, and these two classes alternate with each other every generation in the manner just indicated. Secondly, the members of one class can in principle[257] marry into only one of the classes of the other phratry. The Ippai must marry into the Kubbi class and the Murri into the Kumbo class. It is because this organization profoundly affects matrimonial relations that we give the group the name of matrimonial class. Now it may be asked whether these classes do not sometimes have totems like the phratries and clans. This question is raised by the fact that in certain tribes of Queensland, each matrimonial class has dietetic restrictions that are peculiar to it. The individuals who compose it must abstain from eating the flesh of certain animals which the others may consume freely.[258] Are these animals not totems?