REPORT OF THE SECRETARY. 115 



The Fundamental Factor of Insect Evolution, by S. S. Chetverikov. 8 pp., 1 pi. 



(Publ. 2566.) 

 The Psychic Life of Insects, by E. L. Bouvier. 8 pp. (Publ. 2567.) 

 Sexual Selection and Bird Song, by Chauncey J. Hawkins. 12 pp. (Publ. 



2568.) 

 Marine Camoufleurs and Their Camouflage : The Present and Prospective Sig- 

 nificance of Facts Regarding the Coloration of Tropical Fishes, by W. H. 



Longley. 10 pp., 5 pis. (Publ. 2569.) 

 Foot-Plow Agriculture in Peru, by O. F. Cook. 4 pp., 4 pis. (Publ. 2570.) 

 Sun Worship of the Hopi Indians, by J. Walter Fewkes. 33 pp., 11 pis. (Publ. 



2571.) 

 A Constitutional League of Peace in the Stone Age of America : The League of 



the Iroquois and Its Constitution, by J. N. B. Hewitt. 18 pp. (Publ. 2572.) 

 The Problem of Degeneracy, by H. F. Tredgold. 15 pp. (Publ. 2573.) 

 History in Tools, by W. M. Flinders Petrie. 10 pp. ( Publ. 2574. ) 

 The Background of Totemism, by E. Washburn Hopkins. 11 pp. (Publ. 2575.) 

 A Great Naturalist : Sir Joseph Hooker, by Sir E. Kay Lankester. 16 pp. 



(Publ. 2576.) 



REPORT FOR 1919. 



The general appendix to the report for 1919, which was still in 

 press at the close of the year, contains the following papers : 



Modern theories of the spiral nebulae, by Heber D. Curt's. 



A determination of the deflection of light by the sun's gravitational field, from 

 observations made at the total eclipse of May 29, 1919, by Sir F. W. Dyson, 

 A. S. Eddington, and C. Davidson 



Wireless telephony, by N. H. Slaughter. 



Radium and the electron, by Sir Ernest Rutherford. 



The " HD-4." A 70-miler with remarkable possibilities developed at Dr. Gra- 

 ham Bell's laboratories on the Bras d'Or Lakes, by William Washburn Nut- 

 ting. 



Natural resources in their relation to military supplies, by Arthur D. Little. 



Glass and some of its problems, by Sir Herbert Jackson. 



The functions and ideals of a national geological survey, by F. L. Ransome. 



The influence of cold in stimulating the growth of plants, by Frederick V. 

 Coville. 



Floral aspects of British Guiana, by A. S. Hitchcock. 



Milpa agriculture, a primitive tropical system, by O. F. Cook. 



On the extinction of the mammoth, by H. Neuville. 



A preliminary study of the relation between geographical distribution and mi- 

 gration, with special reference to the Palaearctic region, by R. Meinertzhagen. 



The necessity of State action for the protection of wild birds, by Walter E. 

 Collinge. 



Glimpses of desert bird life in the Great Basin, by Harry C. Oberholser. 



The Division of Insects in the United States National Museum, by J. M. 

 Aldrich. 



The seventeen-year locust, by R. E. Snodgrass. 



Entomology and the war, by L. O. Howard. 



Two types of southwestern cliff houses, by J. Walter Fewkes. 



On the race history and facial characteristics of the aboriginal Americans, by 

 W. H. Holmes. 



The opportunity for American archeological research in Palestine, by James 

 A. Montgomery. 



