Some sea-flying birds have been captured over five hundred miles from land and seeds of a buttercup and of the sea blite recovered from their stomachs. One student of the flora of Spitzbergen has stated that nearly all the plants of that cold region have come from the northern part of the Scandinavian peninsula through their carriage by birds. One of the commonest plants of that region is the crowberry, which is a favorite food of birds. The plant is found throughout the Arctic regions and on high mountain tops to the south of it, such as the Alps, our own Adirondacks and White Mountains, and many others. There are some islands in the Pacific known to have received a few of the plants now growing on them by birds carrying the seeds from other regions, often thousands of miles away. Several species of birds are known to make sustained oversea flights from Labrador to South America, and one from Alaska to Hawaii. In such flights stopping is impossible, so that the carrying of fresh seeds and spores is always likely and probably more quickly accomplished than by any other means of transport. In New Zealand a northern European bird was once found with the seeds of two species of marsh arrow grass in its stomach, both of which germinated. The plants are native in the cooler parts of the north temperate zone. Not far from New York, at Montauk Point, Long Island, there was found a few years ago some plants of the cloudberry, a kind of blackberry with amber-colored fruits, which is otherwise unknown in that region but is common enough in the Arctic and on mountain tops northward. That point of land, extending out to sea, is a favorite stopping place for migrating birds and to them was undoubtedly due the introduction of the plant so far south of its true home. Scores of similar cases could be cited which confirm the observations of naturalists all over the world that birds are among the greatest aids to plants in securing wide dispersal. Of course the factors of favorable or unfavorable conditions, once the seed is deposited in the new home, operate to keep plants from the tropics from settling permanently in colder regions and _vice versa_, but we cannot escape the conclusion that the sky is filled during certain seasons with millions of seed carriers that have, in many cases, populated their stopping places with foreign plants.