* * * * * We already owe a great deal to passion: more than men ever realize. Wasn't it Darwin who once even risked the conjecture that the vocal organs themselves were developed for sexual purposes, the object being to call or charm one's mate. Hence--perhaps--only animals that were continuously concerned with their matings would be at all likely to form an elaborate language. And without an elaborate language, growth is apt to be slow. If we owe this to passion, what follows? Does it mean, for example, that the more different mates that each simian once learned to charm, the more rapidly language, and with it civilization, advanced? _TWELVE_ A doctor, who was making a study of monkeys, once told me that he was trying experiments that bore on the polygamy question. He had a young monkey named Jack who had mated with a female named Jill; and in another cage another newly-wedded pair, Arabella and Archer. Each pair seemed absorbed in each other, and devoted and happy. They even hugged each other at mealtime and exchanged bits of food. After a time their transports grew less fiery, and their affections less fixed. Archer got a bit bored. He was decent about it, though, and when Arabella cuddled beside him he would more or less perfunctorily embrace her. But when he forgot, she grew cross. The same thing occurred a little later in the Jack and Jill cage, only there it was Jill who became a little tired of Jack. Soon each pair was quarreling. They usually made up, pretty soon, and started loving again. But it petered out; each time more quickly. [Illustration: Archer felt bored] Meanwhile the two families had become interested in watching each other. When Jill had repulsed Jack, and he had moped about it awhile, he would begin staring at Arabella, over opposite, and trying to attract her attention. This got Jack in trouble all around. Arabella indignantly made faces at him and then turned her back; and as for Jill, she grew furious, and tore out his fur. But in the next stage, they even stopped hating each other. Each pair grew indifferent. Then the doctor put Jack in with Arabella, and Archer with Jill. Arabella promptly yielded to Jack. New devotion. More transports. Jill and Archer were shocked. Jill clung to the bars of her cage, quivering, and screaming remonstrance; and even blase Archer chattered angrily at some of the scenes. Then the doctor hung curtains between the cages to shut out the view. Jill and Archer, left to each other, grew interested. They soon were inseparable. The four monkeys, thus re-distributed, were now happy once more, and full of new liveliness and spirit. But before very long, each pair quarreled--and made up--and quarreled--and then grew indifferent, and had cynical thoughts about life. At this point, the doctor put them back with their original mates.