We must suppose that laughter has always existed in man, at least as long as he has been physically constituted as he is now, for it might always have been produced by tickling the papillae of the nerves, which are said to be more exposed in man than in other animals. When we have stated the possibility of this pleasurable sensation being awakened under such circumstances, we have, in fact, asserted that it was in course of time thus called into existence. But the enjoyment might have been limited to this low phase, for the mind might have been so vacant, so deficient in emotion and intelligence that the moral and intellectual conditions necessary for a higher kind of laughter might have been wanting. This seems to be the case among some savages at the present day, such as the New Zealanders and North American Indians. The earliest laughter did not arise from what we call the ludicrous, but from something apparently physical--such as touch--though it does not follow that it would never otherwise have existed at all, for, as the mind more fully developed itself, facial expressions would flow from superior and more numerous causes. Nor can we consider that what is properly called mirth was shown in this primitive physical laughter, which was such as may be supposed to have existed when darkness was on the face of the intellectual world. How great, and of what continuance, was this primeval stagnation must be for ever unknown to us, but it was not destined to prevail. Light gradually dawned upon the mental wastes, and they became productive of beauty and order. As greater sensibility developed itself, emotion began to be expressed; first, probably at an adult period of life, by the sounds belonging to the corresponding feelings in the bodily constitution. Tears and cries betoken mental as well as physical anguish, and laughter denoted a mixed pleasurable feeling either in mind or body. There is a remarkable instance of this transference from the senses to the emotional feelings in the case of what is called sardonic laughter, in which a similar contortion of countenance to that caused by the pungency of a Sardinian herb is considered to denote a certain moral acerbity. Here there is an analogy established between the senses and emotions in their outward manifestation, just as there is in language in the double meaning of such terms as bitter and sweet.