VI CONTENTS 



Page 

 Soil erosion: The growth of the desert in Africa and elsewhere, by Sir 



Daniel Hall 303 



The future of paleontology, by Joseph A. Cushman 317 



The meteorology of great floods in the eastern United States, by Charles F. 



Brooks and Alfred H. Thiessen 325 



Eyes that shine at night, by Ernest P. Walker 349 



The Chinese mitten crab, by A. Panning 361 



The biology of light-production in arthropods, by N. S. Rustum Maluf 377 



The black widow spider, by Fred E. D' Amour, Frances E. Becker, and 



Walker van Riper 405 



The language of bees, by K. von Frisch 423 



Forest genetics, by Lloyd Austin 433 



The story of the maidenhair tree, by Sir Albert C. Seward 441 



The water-culture method for growing plants without soil, by D. R. Hoag- 



land and D. I. Arnon 461 



"Root-pressure" — an unappreciated force in sap movement, by Philip R. 



White 489 



The reproduction of virus proteins, by W. M. Stanley 499 



Modern medicine— the crossroads of the social and the physical sciences, by 



Charles Austin Doan 511 



History and stratigraphy in the Valley of Mexico, by George C. Vaillant__ 521 



The Folsom problem in American archeology, by Frank H. H. Roberts, Jr_ _ 531 



The Roman Orient and the Far East, by C. G. Seligman 547 



An ancient Chinese capital: Earthworks at Old Ch'ang-an, by Carl Whiting 



Bishop 569 



The natural limits to human flight, by H. E. Wimperis 579 



The historic American merchant marine, by Frank A. Taylor 595 



