We have rapidly sketched this labor of organogenesis, by which language has passed from the amorphous state to the progressive constitution of specialised terms and grammatical functions: an evolution wholly comparable with that which, in living bodies, starts from the fecundated ovule, to attain by division of labor among the higher species to a fixed adjustment of organs and functions. “Languages are natural organisms, which, without being independent of human volition, are born, grow, age, and die, according to determined laws.” (Schleicher.) They are in a state of continuous renovation, of acquisition, and of loss. In civilised languages, this incessant metamorphosis is partially checked by enforced instruction, by tradition, and respect for the great literary works. In savage idioms where these coercive measures are lacking, the transformation at times occurs with such rapidity that they become unrecognisable at the end of a few generations. Spoken language, as a psycho-physiological mechanism, is regulated in its evolution by physiological and psychological laws. Among the former (with which we are not concerned), the principal is the law of phonetic alteration, consisting in the displacement of an articulation in a determined direction. It is dependent on the vocal organ; thus, after the Germanic invasion, the Latin which this people spoke fell again under the power of physiological influences which modified it profoundly. Among the latter, the principal is the law of analogy, the great artisan in the extension of languages. It is a law of economy, the basis of which is generalisation, the faculty of seizing on real or supposed resemblances. The word remains invariable, but the mind gives it different applications: it is a mask covering in turn several faces. It suffices to open a dictionary to see how ingenious and perilous is this unconscious labor. Such a word has only a few lines; it has no brilliant record. Such another fills pages; first we see it in its primitive sense; then—from analogy to analogy—from accident to accident—it departs from it more and more, and ends by having quite a contrary meaning.[66] Hence it has been said that “the object of a true etymology is to discover the laws that have regulated the evolution of thought.” Among primitive people, the process that entails such deviations from the primitive sense, is sometimes of striking absurdity; or at least appears to us as such by reason of the strange analogies that serve the extension of the word. Thus: certain Australian tribes gave the names of mussels (_muyum_), to books because they open and close like shell-fish; and many other no less singular facts could be cited. Much more might be said as to the rôle of analogy, but we must adhere to our subject.