REPOET OF THE SECRETARY 143 



Mounds and Other Ancient Earthworks of the Uultc-d Stntes, by D:i\id I. 

 IJushuoll. jr. 

 Geocliroiiology, by Grand de Goer. 



The IMiysi('l(),i,'y of the Ductless Ghiiids, by N. B. Taylor. 

 Arrheiiius Memorial Lecture, by Sir James Walker. 

 Theodore William Richards, by Gregory P. Baxter. 



Report for 19'20. — The report of the executi\i' coininittce and 

 proceedings of the Board of Regents of the Institution and the re- 

 port of the secretary, both forming parts of the annual repoit of the 

 TJoard of Regents to Congress, were issued in December, 1921). 



Report of the executive committee aud proceedings of the Board of Re;^outs 

 of the Smithsonian Institution for the year ending June 30, 19129. 12 pp. 

 (Publ. 8082.) 



Report of the Secretary of the Smithsonian Institution for the yrar ondinj,' 

 June 30, 1929. 144 pp., 2 text figs. (Publ. 3031.) 



The general appendix to this report, which was in pres.s at the 

 dose of tlie year, contains the following papers: 



ITie Physics of the Uuirer.^e, by Sir .lames Jeans. 



Counting the Stars aud .some Conclusions, by Frederick H. Scares. 



The Lingerin;: Dryad, by Paul R. Utyl. 



What is Litjht? by Arthur II. Comjiton. 



Artiticial Cold, by Gordon B. Wilkes. 



Pliotosynthesis, by E. C. C. Baly. 



Newly Discovered Chemical Elements, by N. M. BliKh. 



Synthetic Perfimies, by H. Stanley Redgrove. 



X Rayin;,' the Earth, by Rejiinald A. Daly. 



Extinction and Extermination, by I. P. Tolmachoff. 



The Gulf Stream and its Problems, by H. A. Marnier. 



The Mystery of Life, by F. G. Donnaii. 



The Transition from Live to Dead: tlie Nature of Filtrablo Viruses, by 

 A. E. Boycott. 



Heritable Variations, their Production by X rays, aud their Relation to 

 Evolution, by IL J. MuUer. 



Social Parasitism in Bird.s, by Herbert Friedmaun. 



How Insects Fly, by R. E. Suodgrass. 



Climate and Migrations, by J. C. Curry. 



Ur of the Chalde<'s : More Royal Toml)s, l)y C. L<'onard Woolloy. 



The Population of Ancient America, by II. J. Spindcn. 



The Al)origines of the Ancient Island of Hi-spaniola, by IlerlK'rt W. Krietjer. 



The Bejcinnini^ of the Mechanical 'J'ransport At;e in America, by Carl W. 

 Mitman. 



The Servant in the House; a Brief History of the Sewing Machine, by 

 Frederick L. Lewton. 



Thomas Chrowder Chamberlin (1S4:} 1!)28), by Bailey Willis. 



Ilideyo Noguchi, by Simon Flexner. 



SPECIAL PUBLICATIONS 



Explorations and Field Work of the Smithsonian Institution in 1929. 222 pp., 

 2O0 text figs. (Publ. 30C0.) 



