In dealing with the origin of the classes it is important to bear in mind that they are undoubtedly later than the phratries. This is clear, not only from the considerations urged on p. 71, but also from the fact that the areas covered by the same classes are in the three most important cases immensely larger than any covered by a phratriac system. We may therefore dismiss at the outset Herr Cunow's theory, which makes the classes the original form of organisation.

To explain the origin of the classes, as of the phratries, two kinds of theories have been put forward, which are in this case also classifiable as reformatory and developmental respectively. The former labour under the same disadvantages, so far as they assume that particular marriages were regarded as immoral or objectionable, as do the similar hypotheses of the origin of phratries.

What is the effect of dividing a phratry into two classes? Firstly and most obviously, to reduce by one half the number of women from whom a man may take his spouse. Secondarily, to put in the forbidden class both his mother's generation and his daughters' generation. It must however not be overlooked that it is the whole class of individuals that are thus put beyond his reach and not those only who stand to him in the relation of daughters in the European sense.