At the present moment a satisfactory grouping of the world’s kinship systems is impossible, owing to our lack of knowledge of many areas. The task is also rendered very difficult by the frequent coexistence of distinct and even contradictory principles in the same ‘system’. Each of these may be defined separately, but to weld both or all of them into a unified whole defies our efforts. For example, the Masai of East Africa, in referring to the paternal uncle, simply combine the stems for ‘father’, _baba_, and ‘brother’, _alasche_, thus forming by juxtaposition of these primary terms the compound expression _ol alasche le baba_, which means literally ‘the brother of the father’. This mode of defining a relative’s status by combining primary terms of relationship or a primary term with a qualifying adjective as in our ‘grandfather’, is technically known as ‘descriptive’, and ethnologists are wont to speak of descriptive systems. As a matter of fact, this descriptive principle is highly characteristic of the Masai--but not when relatives are directly addressed by them. In such vocative usage, as it may be called, the father’s brother is called _baba_ like the father himself; the mother’s brother is not designated by a phrase composed of primary stems but by a new stem, _abula_, which is also used reciprocally for the nephew; while _koko_ serves to call both a paternal and a maternal aunt. These connotations introduce into the Masai ‘system’ a discordant principle by which relatives, instead of being defined descriptively, are grouped together in classes. But this ‘classificatory’ feature by no means characterizes all the vocative nomenclature. By far the majority of relatives are addressed by terms suggestive of the presents of live stock presented to them by the speaker; if the gift consisted of a bull, the word used is _b-ainoni_, from _oinoni_, bull; if an ass was given away, the vocative term is _ba-sigiria_, from _sigiria_, ass; and so forth. Accordingly, the vocative terms cited above are only employed by children, who have not yet presented stock to their kin.[3] In short, Masai terminology is molded by at least three entirely disparate principles. We shall, accordingly, do well to amend our phraseology and to speak rather of kinship categories, features, or principles of classification than of types of kinship systems.