The quail lays some twelve or fifteen eggs, and seems to be aware of the fact that some of her eggs are missing when several have been removed from the nest. When one of these birds has laid six or eight eggs, if two or three be removed she will abandon the nest and deposit the remainder of her eggs elsewhere. This behavior on the part of the bird has been attributed to her sense of smell; she, detecting the presence of an enemy by the scent of his hand left behind in the nest, recognizes the danger, and therefore abandons the nest. But numerous experiments along this line teach me that smell has nothing to do with it whatever. I have removed eggs with a long iron ladle, the bowl of which I had carefully refrained from touching, and also with sticks freshly cut in the wood, and yet the birds would invariably abandon their nests. On the contrary, when all, or nearly all, the eggs have been laid, several may be removed either with the ladle or with the naked hand, and yet the bird will not abandon her nest. She seems to be able to count up to six or eight; beyond this latter number her faculty of computing does not extend. After the full laying has been deposited in the nest and the process of incubation has become established, a large number of the eggs may be removed, and yet the bird will continue to set until the remaining eggs have been hatched out. The faculty of computing seems to be present in other birds to some extent; the domesticated guinea-fowl and the turkey sometimes possess it in a marked degree, though in most of these fowls domestication has almost entirely eradicated it. The domestic barnyard hen has had her nest robbed for such a long period of time that she has lost the faculty of counting. But even this meek provider of food for mankind is able, in some instances, to count one: she will not lay in her nest unless a nest-egg be left to delude her. The nest-egg may be wholly factitious and made of china, marble, chalk, stone or iron painted white; the hen does not seem to care so long as it bears some resemblance to an egg.