_Useful Birds and their Protection_ (Forbush), pages 354-421. _Birds of Ohio_ (Dawson), pages 548-551; "Herring Gull." _Bird Book_ (Eckstorm), pages 23-29; "The Herring Gull." _American Birds_ (Finley), pages 211-217; "Gull Habits." _Game-Laws for 1920_ (Lawyer and Earnshaw), pages 68-75; "Migratory-Bird Treaty Act." _Tales from Birdland_ (Pearson), pages 3-27; "Hardheart, the Gull." _Educational Leaflet No. 29_; "The Herring Gull." (National Association of Audubon Societies.) PETER PIPER _Actitis macularia_, the Spotted Sandpiper. Educational Leaflet No. 51. (National Association of Audubon Societies.) "A leisurely little flight to Brazil." Peter, the gypsy, and Bob, the vagabond, are both famous travelers, and might have passed each other on the way, coming and going, in Venezuela and in Brazil. Peter, like Bob, is a night migrant, stopping in the daytime for rest and food. For references to literature on bird-migration, the list under the notes to "Bob, the Vagabond," may be used. GAVIA OF IMMER LAKE _Gavia immer_, the Loon. _The Bird_ (Beebe). "Hesperornis--a wingless, toothed, diving bird, about 5 feet in length, which inhabited the great seas during the Cretaceous period, some four millions of years ago." (Legend under colored frontispiece.) _Life Histories of North American Diving Birds_ (Bent), pages 47-60. _Bird Book_ (Eckstorm), pages 9-13. _By-Ways and Bird-Notes_ (Thompson), pages 170-71. "The cretaceous birds of America all appear to be aquatic, and comprise some eight or a dozen genera, and many species. Professor Marsh and others have found in Kansas a large number of most interesting fossil birds, one of them, a gigantic loon-like creature, six feet in length from beak to toe, taken from the yellow chalk of the Smoky Hill River region and from calcareous shale near Fort Wallace, is named _Hesperornis regalis_." _Educational Leaflet No. 78._ (National Association of Audubon Societies.) If twenty years of undisputed possession seems long enough to give a man a legal title to "his" land, surely birds have a claim too ancient to be ignored by modern beings. Are we not in honor bound to share what we have so recently considered "ours," with the creatures that inherited the earth before the coming of their worst enemy, Civilization? And in so far as lies within our power, shall we not protect the free, wild feathered folk from ourselves? EVE AND PETRO _Petrochelidon lunifrons_, Cliff-Swallow, Eave-Swallow. _Bird Studies with a Camera_ (Chapman), pages 89-105; "Where Swallows Roost." _Handbook of Nature-Study_ (Comstock), pages 112-113. _Bird Migration_ (Cooke), pages 5, 9, 19-20, 26, 27; Fig. 6. _Our Greatest Travelers_ (Cooke), page 349; "Migration Route of the Cliff Swallows." _Bird Book_ (Eckstorm), pages 201-12. _Bird-Lore_, vol. 21, page 175; "Helping Barn and Cliff Swallows to Nest." UNCLE SAM _Haliaeetus leucocephalus_, the Bald Eagle.