Judging by the evidence at present available, it seems likely that the arctic terns of eastern North America originally found their way here from the Old World, probably by way of Iceland and Greenland. Consequently when the time comes for them to migrate to winter quarters they do not go directly south as do the common (_Sterna hirundo_) and Forster's terns (_S. forsteri_), but instead, they fly back eastward along their ancestral route across the Atlantic to the shores of Europe and then go south along the African coast to their winter home; those that breed in the northwestern part of the continent, as in Alaska, probably migrate chiefly down the western coast, as the species is not infrequently reported on the coast of California and also on the western coast of South America. [Illustration: B4750M Figure 15.— Distribution and the migration of the arctic terns of eastern North America. The route indicated for this bird is unique, as no other species is known to breed abundantly in North America and to cross the Atlantic Ocean to and from the Old World. The extreme summer and winter homes are 11,000 miles apart, and as the route taken is circuitous, these terns probably fly at least 25,000 miles each year.] The evidence yielded by banding consists of only three definite cases, but their interpretation seems to permit but one conclusion: All three birds were banded as downy chicks, one on July 3, 1913, at Eastern Egg Rock, Maine,[3] and the other two at the Red Islands, Turnevik Bay, Labrador, on July 22, 1927, and July 23, 1928. The first was found dead in the Niger River delta, West Africa, in August 1917, while the Labrador birds were recovered near La Rochelle, France, on October 1, 1927, and at Margate, near Port Shepstone, Natal, South Africa, on November 14, 1928. The flight shown by this last record is the longest known, the trip, between 8,000 and 9,000 miles, being accomplished in less than 3 months. [Footnote 3: Recorded at the time of banding as a common tern, a natural error, as the downy young of common and arctic terns look almost exactly alike.] Probably no other animal in the world enjoys as many hours of daylight as does the arctic tern, since for these birds the sun never sets during their nesting season in the northern part of the range, while during their sojourn in the south, daylight is continuous. During several months of the year they have 24 hours of daylight and during the other months considerably more daylight than darkness. =ROUTES OF MIGRATION=