Before we enter upon another active campaign of bird-nesting, it is fitting that we should pause a moment to reflect upon the true aim of our toil, risks, and trouble, as well as delight and recreation. How many of us can define the phrase "collecting for scientific purposes," which, like liberty, is the excuse for many crimes? If it is true, as has been asserted, that oology as a scientific study has been a disappointment, I am convinced that it is not on account of its limited possibilities, but simply because the average oologist devotes so much time to the collection and bartering of specimens that no time is left for the actual study of the accumulating shells. In other words, he frequently undertakes a journey without aim or object. The oologist has done much toward clearing up the life-history of many of our birds, but as observations of this nature can often be accomplished without the breaking up of the home of the parent bird, it alone will not suffice as an excuse for indiscriminate collecting. After preparing the specimen for the cabinet his responsibility does not end but only begins. A failure to add something to the general knowledge is robbing the public as well as the birds. He who talks fluently of the enforcement of strict laws for the preservation of our wild birds, their nests and eggs, and fails to protect and encourage those about his premises, falls short of his duty; and if his cabinet contains bird skins or egg shells which might just as well have remained where Nature placed them, he is inconsistent, demanding that others abstain that he may indulge. In conclusion I would say that when an oologist constantly keeps in mind and acts under the assumption that the birds are his best friends and not his deadly enemies, he cannot go far wrong, and the means he employs will be justified in the light of subsequent study and research of data and specimens. If any of us fall short in this we have only ourselves to blame. Let us then collect with moderation and fewer eggs and more notes be the order of the day. [Illustration: BLUE-WINGED YELLOW WARBLER. Life-size. FROM COL. CHI. ACAD. SCIENCES. 6-99 COPYRIGHT 1899, NATURE STUDY PUB. CO., CHICAGO.] THE BLUE-WINGED YELLOW WARBLER. (_Helminthophila pinus._) Not a great deal is known about many of the warblers, and comparatively little has been observed of this member of the very large family, comprising more than one hundred species. This specimen is also recognized by the name of the blue-winged swamp warbler. Its habitat is eastern United States, chiefly south of 40 degrees and west of the Alleghanies, north irregularly to Massachusetts and Michigan, and west to border of the great plains. In winter it lives in eastern Mexico and Guatemala.