This bit of conjectural inquiry will begin by trying to answer the question: By what process did the laugh, from being a general sign of pleasure, become specialised into an expression of the uprising of the mirthful, fun-loving or jocose spirit? It will then address itself to the problem: What has been the course of development of the spirit of fun and of its characteristic mode of utterance? It would not, of course, be possible to attempt even a conjectural account of these far-off and unchronicled events, but for the new instruments of hypothetical construction {156} with which the Theory of Evolution has furnished us. In attempting so hazardous a task we have, at least, the example of one of the most modest of men to draw us on. Charles Darwin has taught us how to be at once daring and cautious in trying to penetrate the darkness of the ages behind us; and one can wish nothing better than to be able to walk worthily in his steps. It will be evident that in essaying an effort which can at best end in only a plausible guess we must use every available clue. This means, not merely that we try to trace back the history of mirthful utterance, alike in the evolution of the individual and of the species, to its rude inchoate forms, but that we search for vestiges of utterances vaguely resembling human laughter in the animal world. This last suggestion may well seem to the reader like another blow to man’s early pride of race. The worthy naturalist who called his species the “laughing animal” did not probably trouble himself about the question of the dignity of the attribute. Since laughing was one of the things that only man could do, it served as a convenient way of describing him. Yet, since the later evolutional psychology has led us to be more generous in recognising in the lower animals something closely similar to our own processes of reasoning, we need not be greatly shocked to hear that it is actually crediting other species than our own with a simple sense of fun, and a characteristic manner of expressing the feeling; that is to say, an utterance answering to our laugh.