Once more, the child’s extension of a word from an idea to its correlative has its parallel in the adult’s use of language. As the vulgar expression ‘I’ll larn you’ shows (_cf._ the Anglo-Saxon _leornian_), a word may come to mean both to teach and to become taught. A like embracing of agent and object acted upon by the same word is seen in the ‘active’ and ‘passive’ meanings of words like the Latin _penetrabilis_ (‘piercing’ and ‘pierceable’), and in the ‘objective’ and ‘subjective’ meanings of ‘pleasant’ and similar words. We are beginning, like the little girl quoted above, to speak of a ‘sore’ topic. Lastly, the movement of thought underlying the saying of the little Italian girl, ‘nasty baby,’ seems to be akin to that of the savage when he supposes that he appropriates the qualities of that which he eats. The changes here touched upon have to do with what philologists call generalisation. As supplementary to these there is in the case of the growth of a community-language a process of specialisation, as when ‘physician’ from meaning a student of nature has come to mean one who has acquired and can practically apply one branch of nature-knowledge. In the case of the child we have an analogue of this in the gradual limitation of names to narrower classes or to individuals as the result of carrying out certain processes of comparison and discrimination. Thus ‘ba-ba,’ which is used at first for a miscellaneous crowd of woolly or hairy quadrupeds, gets specialised as a name for a sheep, and the much-abused ‘papa’ becomes restricted to its rightful owner. This process of differentiation and specialisation assumes an interesting form in a characteristic feature of the language-invention of both children and savages, _viz._, the formation of compound words. These compounds are often true metaphors. Thus in the case already quoted where an eye-lid was called an eye-curtain the child may be said to have resorted to a metaphorical way of describing the lid. It is much the same when M. at the age of one year nine months invented the expression ‘bwite (bright) penny’ for silver pieces. A slightly different example is the compound ‘foot-wing’ invented by the child C. to describe the limb of a seal. As a further variety of this metaphoric formation I may quote the pretty name ‘tell-wind’ which a boy of four years and eight months hit upon as a name for the weather-vane. In these and similar cases, there is at once an analogical transference of meaning (_e.g._, from curtain to lid) or process of generalisation, and a limitation of meaning by the appended or qualifying word ‘eye’ and so a process of specialisation.