"Leisure," answered Mr. Glass. "Philander Q. Doesticks and other humorists of his time wrote to amuse pioneers, people rough and elemental in their tastes. Their audience consisted of men who worked hard most of the time, and therefore had to be hit hard by any joke that was to entertain them at all. But as Americans grew more leisurely, and therefore had time to read, see plays, and look at pictures, they lost their taste for crude and violent horseplay, and the new sort of humor came in. Undoubtedly the same thing occurs in every newly settled country--Australia, for example. It is unlikely that the Australian of one hundred years from now will be amused by the things that amuse Australians to-day. "But the humor that entertains the citizens of a country of which the civilization is well established is likely to retain its charm through the years. Mark Twain's stories do not lose their flavor. But Mark Twain was not exclusively a humorist; he was a student of life and he reflected the tragedy of existence as well as its comedy. So does Irvin Cobb, who is the nearest approach to Mark Twain now living. "One source of Mark Twain's strength is his occasional vulgarity. That surely is something that we should have in greater abundance in American humor. I do not mean that our humorists should be pornographic and obscene; I mean merely that they should be allowed great freedom in their choice of themes. There is no humor without vulgarity. Our humorists have been so limited and restrained that we have no paper fit to be compared with _Simplicissimus_ or _Le Rire_. "You see, a vulgar thing is not offensive if it is funny. Fun for fun's sake is a much more important maxim than art for art's sake. The humorists have a greater need for freedom in choice of themes than the serious writers, especially the realistic writers, who are always demanding greater freedom." Mr. Glass returned to the subject of the failure of cosmopolitanism to influence American literature by calling attention to the fact that very few American writers find their themes among their foreign-born fellow-citizens. "Where," he asked, "are the German-Americans and the Italian-Americans? No writer knows these foreign-born citizens well enough to write about them. The best American stories are about native Americans. I admit that my stories are not about people peculiar to New York--you can find counterparts of 'Potash and Perlmutter' in Berlin, Paris, and London. But mine are not among the best stories of American character. The best story of American character is 'Daisy Miller.'"