The birds arranged in this order are also known, under the name of
aquatic birds. They are distinguished by their feet, the toes being
united by a broad membrane, which assists them in swimming. Several live
uniformly on the water, others in companies on the water and on the
land. There are many that may be tamed, but I shall only speak of those
that are able to live without being on the water. The number is thus
confined to six species, easily tamed at any age.