The discussion is now, however, varied by the suggested possibility that man at some time may have existed without any oral language. It is conceded by some writers that mental images or representations can be formed without any connection with sound, and may at least serve for thought, though not for expression. It is certain that concepts, however formed, can be expressed by other means than sound. One mode of this expression is by gesture, and there is less reason to believe that gestures commenced as the interpretation of, or substitute for words than that the latter originated in, and served to translate gestures. Many arguments have been advanced to prove that gesture language preceded articulate speech and formed the earliest attempt at communication, resulting from the interacting subjective and objective conditions to which primitive man was exposed. Some of the facts on which deductions have been based, made in accordance with well-established modes of scientific research from study of the lower animals, children, idiots, the lower types of mankind, and deaf-mutes, will be briefly mentioned.
GESTURES OF THE LOWER ANIMALS.
Emotional expression in the features of man is to be considered in reference to the fact that the special senses either have their seat in, or are in close relation to the face, and that so large a number of nerves pass to it from the brain. The same is true of the lower animals, so that it would be inferred, as is the case, that the faces of those animals are also expressive of emotion. There is also noticed among them an exhibition of emotion by corporeal action. This is the class of gestures common to them with the earliest made by man, as above mentioned, and it is reasonable to suppose that those were made by