The cultural understanding and appreciation of the scientific approach.

ScIENcE: A Weekly Journal, since 1900 the official organ Communications relative to advertising should be addressed of the American Association for the Advancement of Science. to THEO. J. CHRISTENSEN, 1515 Massachusetts Avenue, N.W., Published by the American Association for the Advancement Washington 5, D. C. of Science every Friday at Lancaster, Pennsylvania. Communications relative to membership In the Association and to all matters of business of the Association should be Communications relative to articles offered for publication addressed to the Administrative Secretary, AAAS, 1515 Masshould be addressed to Editor, 1515 Massachusetts Avenue, sachusetts Avenue, N.W., Washington 5 D. C. N.W., Washington 5, D. C. Annual subscription, $7.50 Single copies, 25 cents Entered as second-class matter July 18, 1923 at the Post Office at Lancaster, Pa., under the Act of March 3, 1879. o n A pr il 16 , 2 01 7