muscle; the tongue of homo sapiens is a thick muscular mass. A somewhat exaggerated comparison is to a leather strap, in one case, and a frog seated in the mouth in the other case. We have now advanced the question one step farther, to ask what may be the advantage, if any, in the form of the human tongue.
The animal tongue is certainly just as well adapted to the purposes of obtaining and preparing food, as the human. In some cases, it is even more efficient. But the human tongue is an important instrument in the production of the most human of all attributes, language. Language is not merely the means of communicating thought; it is, as philologists have long known, and as psychologists have been forced somewhat unwillingly to admit, the principal means of thinking. While it is possible to think without language, languageless thought is primitive and inefficient in the complex conditions of civilization, and it is by no means an exaggeration to say that the development of language is a large part of the development of thought.
Of course, it is not to be said that in any specific case a large tongue is an index of efficient thinking, or that a relatively smaller chin indicates necessarily a relatively smaller tongue, or that the converse of either of these propositions is true. But on the whole, the development of the chin
