The human baby starts its expressive habits by emitting with wide-open mouth an undifferentiated shriek of pain. A little later it yells in the same way at any kind of discomfort. It begins before the end of the first year to croon when it is contented. As it grows older it begins to make different sounds when it experiences different emotions. And with remarkable rapidity its repertoire of articulatory movements has greatly increased. Speech that begins in the child as a mere vague vocal expression of emotion soon begins to exhibit a marked element of mimicry. The child begins to associate the words uttered by his nurse or parents with the specific objects they point to. He comes to connect "milk," "sleep," "mother" with the experiences to which they correspond. The child thus learns to react to certain sounds as significant of certain experiences. Unlike Adam, he does not have to give names to animals, or for that matter to anything else on earth. They all have specific names in the particular language in which he happens to be brought up. In the case of other habits, largely through trial and error, he learns to associate given sounds expressed by other people about him with given experiences, pleasant or unpleasant. He learns further to imitate, so far as possible, these sounds, as a means of more precisely communicating his wants or securing their fulfillment. In this connection students of language frequently have raised the question of how man first came to associate a given sound-sequence with a given experience. Like fire, language was once conceived to be a divine gift. Another theory postulated a genius who took it into his head to give the things of earth their present inevitable names. One other theory equally dubious held that language started in onomatopoetic expressions like "Bow-wow," for dog. Still another hypothesis once highly credited held that the sounds first uttered were the immediate and appropriate expressions called out by particular types of emotional experience. The validity of the last two theories has been rendered particularly dubious. The very instances of imitative words cited, words like "cuckoo," "crash," "flash," were, in their original forms, quite other than they are now. And that words are not immediately apposite expressions of the emotions which they represent, has been generally recognized. In gesture language, the gesture has to remain fairly imitative or expressive to be intelligible. But an examination of half a dozen casual words in contemporary languages shows how arbitrary are the signs used, and how little appositeness or relevance they bear in their sound to the sense which they represent. The detailed study of the perfectly regular changes that so largely characterize the evolution of language, have revealed the inadequacy of any of these views. There seems to be, in fact, no explanation of the origin of the language any more than there is of the origin of life. All that linguistic science