As yet, from the great number of species of water fowl man has really domesticated but two characteristic groups, the species of geese and of ducks. Swans have been brought to a state where they tolerate the presence of man, though they rarely establish any really intimate relations with him. Some other species, as, for instance, the grebe, have been taught to dwell about the homes of man, accepting food from his hands. It is likely that more of these water fowl would have come into human associations were it not for the fact that they are naturally migratory, and when, after a season of domestication, they join a passing flock, they never return to the place where they have been kept. [Illustration: Swans] The swan, like the peacock, has been bred for ornament rather than for use. In fact, the bird has no other merit than its exceeding grace. We cannot believe that much pains was ever taken with this creature to break up the migratory instincts which are common in the wild kindred species. We have to suppose that the bird in its pristine form was without the impulse to undertake distant journeys in the winter season, or that it abandoned ancient habits with no great difficulty. We obtain some light on this point by noting the fact that among the migratory species it not infrequently happens that, while the greater number of individuals undertake the annual journey, certain of them will remain on the ground where they were born. Those which remain would be more likely to mate with those which were like-minded than with others that journeyed afar. In this way small local breeds might well be originated which would differ from their migratory kindred not only in the measure of the wandering instincts, but in the capacity for flight which their kindred preserve. There is some reason to believe that this process of selection naturally and somewhat frequently takes place. In certain cases it may lay the foundation of new species, or at least of distinct varieties; more commonly, however, the individuals which have abandoned the migratory life are likely to perish from the severity of climate or the other unfavorable conditions that their mates avoid by their wanderings. [Illustration: The Original Wild Rock Dove (_Columba livia_) and Some of its Domestic Descendants]