My mother's brother is my _vungo_; my sister's son is my _vungo_; my daughter's husband is my _vungo_. Under our system there seems little akin between these three relationships, but in the Fijian system they are one and the same. D.^{x} (m) = C.^{o} (f), sister of E.^{o} = F.^{x} (f) | | A.^{x} B.^{o} (f) Concubitants. A.'s mother's brother, A.'s _vungo_, has a daughter B., who is concubitant with A. Whether she marries him or not, A was born her husband, and he is therefore her father's _vungo_, son-in-law and nephew. It is to be remembered that marriage is never permitted between relations of different generations. Under no circumstances must _vei-vungoni_ marry, though under the rules of exogamous marrying classes they would, unless specially forbidden, have been permitted to marry. In the above table, A. being an X., his mother's brother is an O. On no account must the latter marry G., A.'s sister, who is an X., but if A.'s _vungo_ has a daughter B. O., the marriage between A. and B. at once becomes obligatory. Here is to be found a reason for the curious custom of the avoidance of a mother-in-law among the Australians and other tribes. Many theories have been advanced for this, but, with the exception of Mr. Fison, I believe that no one has propounded the true explanation. It is that in uterine descent a man's mother-in-law belongs to the class from which he must take his wife. But she, being of a different generation, is tabu to him; hence he must avoid her absolutely, lest he be tempted by her charms to break through the law of the system. This marriage system is practised generally throughout the Fiji Islands, with the following exceptions and modifications:-- In the province of Namosi the descendants of two brothers or of two sisters are regarded as tabu throughout as many generations as their parentage can be remembered, and are strictly forbidden to intermarry. The children of concubitants who have neglected to intermarry do not, as in Mbau, become tabu, but are made to repair their parents' default by themselves becoming concubitants. [Pageheader: CONCUBITANCY UNKNOWN IN POLYNESIA] In Lau, Thakaundrove, and in the greater portion of Vanualevu, the offspring of a brother and sister respectively do not become concubitant until the second generation. In the first generation they are called tabu, but marriage is not actually prohibited. The children of two brothers or of two sisters are, as in Mbau, strictly forbidden to intermarry.